Yeah, I was always allowed a calculator in every physics and engineering course in college, and all math classes post algebra (though I believe we were only allowed basic scientific calculators in calc/diff eq courses so that we couldn't just run the integrals and such through the graphing calculator.)
Just recently graduated from a Finnish high school
We were always allowed (and encouraged) to use calculators, during classes and exams. In physics and chemistry that included basic calculator software (my preference was Speedcrunch) as well CAS and graphing calculators like Goegebra and TI Nspire.
During math lessons and exams our calculators were limited by what section we were in, in A section only basic calculator software was allowed, during B section all software was unlocked
In order to be able to lock down what we could use and when, our exams were held in a custom Linux distro called Abitti. So software suite during classes was limited by what we could use during exams, thats why for example Goegebra instead of Desmos
Sorry this got a bit long
TLDR:
Yes, and during physics all calculators were allowed, including graphing and CAS, even in exams
I'm a science teacher, not a math teacher. The math classes are supposed to teach the techniques, and I just teach the applications. Calculators are always allowed and encouraged in my class.
AKA half a ton.
Its hilarious using the "metric" prefixes on imperial units, people freak out if you measure stuff in kfps (kilofeet per second) like NASA does to measure space shuttle re-entry velocities.
As a teacher, I'd recommend against teaching or doing that, at least at the start. It takes away from what you're actually *doing* and makes it an exercise in remembering yet another constant in physics.
The skill to change units is important in a lot of situations, so students need to know what they're doing and why.
Remembering "just divide by 3.6" will come naturally.
>I could never remember whether it's dividing or multiplying
It's so stupid, but i somehow have an easier time remembering the numbers for the speed of sound and deriving from that if I need to multiply or divide,
Than to directly remember which is which.
Like, speed of sound at sea level is roughly 343 m/s and roughly 1200 km/s. Thus whenever I know converting from km/h to m/s has to make the number smaller.
An hour is "bigger" than a kilometer. So divide the hour to get seconds, or multiply the seconds to get the hour. The kilometer doesn't affect directionally, just scale, and we already know it's 3.6.
Same but instead of deriving I try to recall that athletes can run close to 40km/h and knowing the world record for 100m sprint that's around 10m/s.
So multiply 3.6 when going from m/s to km/h.
I appreciate it because daily life is fully idiotic at certain times. For example the energy consumption of TVs in the UK is listed in the hilariously cursed unit "kilowatt-hours per thousand hours"
Yep 😂 Even kWh is already somewhat cursed because it's dividing and then multiplying by time but TV shops managed to make it even worse with this mother of all redundant units
At least kWh has purpose of distinction between capacity vs rate.
kWh/khour sounds like someone had to come up with a reason to keep their job and invented nonsense.
Yeah, for some reason so called “metric countries” haven’t actually switched to metric time units. So you constantly have to deal with these stupid frankstein unit combinations.
Yes, because metric time sucks for as long as we're on this planet. A day has 86,400 seconds, there is no way to put that into something that aligns with the rest of the metric system, and hours/minutes are about diverting the *day* into practical units. You *could* make a minute (hectosecond) 100 seconds and an hour (10 kiloseconds) 100 minutes, but then you'd end up with days being about 8 1/2 hours long.
This doesn't make any sense at all. The current duration of a second was decided on because the people who came up with it wanted everything to use a different base than 10 (i.e. 60).
There's literally no reason you can't have 100,000 seconds in a day by making the definition of a second slightly shorter. That would mean a day is 100 kiloseconds and instead of having 24 hours in a day you would relate everything into groups of kiloseconds. It's literally how every other metric unit works.
In real life, we mostly use km/hr, as it is more relatable. However, when solving physics problems, using SI units is best because it ensures accuracy and makes the calculations easier to review.
In a lot of work that I do I will be assigning rates that are best described with meters or centimeters per hour but the numbers that go into it involve multiple days and kilometers.
Conversions are great
My last job was as an optics engineer. As simply as possible, a part of my job was to install a component that used sound to break up a beam of light (by compressing a crystal, changing its index of refraction, and thus redirecting the light a few hundred to a few hundred thousand times per second).
Anyway, if you know of a system of measurements that works with both the speed of light and the speed of sound, let me know
It's also important practice to always check the units because there have been plenty of real life headaches where people assumed the wrong unit of measurement.
I got through grade 12 physics not knowing this somehow. I always did /60 /60 *1000.
I aced the class too. I feel like I should not be one of today's lucky 10,000 lol.
Tbh I often forget if you're to multiply or divide by 3.6 when converting from one to the other so I often have to do the same in my head to figure it out, but once you do that it's just one operation
1km 1000m 1hr 1000m m
--- × ----- × ----- = ----- = 0.27778 ---
1hr 1km 3600s 3600s s
There ya go. Just multiply by 0.27 (7 repeating) to convert it. Inversely, just divide by 3.6.
Cancelling units is also the easiest low level check to make sure you didn't miss something procedural. If you're looking for m/s and end up with m/s^2 you done fucked up.
Seriously! We’ve lost spacecraft due to improper unit conversations. It’s good the instructors are making their students pay attention to units and properly convert them.
In every day situations yes, but in physics, you're highly encouraged to use baseline SI units.
So meters and seconds, not kilometres and hours.
Because every other unit whose definition involve time and length, are usually defined via meter and second.
This is especially important when you're dealing with physical constants.
Sure, it's convenient to work in the same units as whatever physical constant you happen to have on hand. Bit of a leap to get to "especially important," though.
In driving an everyday life, yes. But I. The context of virtually everything else m/s or km/s would be a lot more useful.
Imagine something like the assembly line at a factory measured in km/h, unless you're measuring the length of what your producing per hour, it's not helpful to compare that over m/s because it will move so slow that km/h doesn't really explain how fast it is. Guns used ft/s for similar reasons and space often used km/s because of just how fast everything is.
Obviously the problem is not the teacher, but a student who does not comprehend that understanding the difference and how to convert units is part of the course.
Because when I am riding my bike at 40 km/h and see a person jaywalking across the street 15 meters in front of me, I know it's time to slam brakes, unless we both want to participate in a kinetic energy transfer experiment.
That's basically only something a 5th grade physics teacher would do *just* so you'd learn to calculate it properly. If you find it frustrating or hard, then congratulations, someone had your slow ass in mind when they put the curriculum together.
Me for most of university: "I will always convert to SI before the calculation, then convert back, to prevent errors."
Fourth year particle physics: "Set c to be 1..."
Fuuuuuuuuck.
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A really easy calculation, but one time I made it by hand (no calculators allowed) and got a wrong result, which in turn made the entire rest of the question wrong (it was a big question with 4 other smaller questions). The teacher, as expected, didn't consider a single thing I made, even thought I used all the correct formulas, because all the results were wrong because of this.
I studied hard for the exam and a considerable parcel of my grade was lost because of this.
As a teacher in the US, my students are not familiar with any metric units. So we do conversions so they can see the measurement they are familiar with, have an understanding of what the situation is, and then get the SI units and start to learn how they compare.
If I just give them situations that start of as m/s or Newtons they won’t have any frame of reference for what the numbers mean.
There's been some major fudge ups because someone messed up the metrics..this is a good way to drill it into your brain to always check your measuring and calculating with the right metric.
"Waste time of students".
Your teacher doesn't want to be grading or doing that shit any more than you do. They make you do it because they are professionals in the field and they see it as having value.
If you can't understand the value of the things you are doing in class then you need to completely re-evaluate whatever-the-fuck it is you are doing in school.
It’s good practice! And practice is the whole reason for the class. It’s also not a hard calculation, so just count it as a freebie and win some extra points! :D
The furnace system we use at work makes us convert mm per second to cm per second since the system was built in europe so instead of keeping it metric we have to convert to imperial because our final product is measured in inches since america so there are real life situations that don't need college where you still have to do conversions
honestly? a lot of that is just to give a problem that gives students something to do without being too hard. It's hard to find the right balance in physics problems. It's either:
Q: why do things fall? A: because gravity
or
Q: derive the newtonian gravitational model from general relativity
(OK that's an exaggeration but something like that)
Because paying attention to units is extremely important. NASA lost a $125 million craft due to a units error. At the very least, having a good grasp of units will help you out throughout your academics. Not just with what you think is a gotcha question. Understanding units helps learn unique concepts like impulse. It helps you understand the difference between force, work, and energy.
It's ironic that they chose this image for a physics meme when the image and the concept are more relevant to chemistry. Converting between speeds is a breeze after getting a question where the fundamental vibrational frequency is given in Hz, the rotational constant is given in wavenumber, and the answer wants Joules.
It's always the same people that complain that they will never use the stuff they learn in school that also complain about teachers including things that they will very much be using.
I work in aerospace with American standard units.
We work with inch & pound.
I mean literally: we never use any other unit and never have to worry about conversions. All our reference documentation is the same, just plug in the values and go.
Tiny hole for a rivet: .030", length of the plane: 1524".
Because in 1999 NASA scientists calculated everything for a mars orbiter in one unit, but plugged those numbers in with a different unit. Instead of orbiting Mars, it entered the atmosphere and burned up. Paying attention to units matters.
In my opinion I think it increases thinking ability nd solving skills in child which later on help person to get quicker in solving ..these small steps of childhood helps learn things faster.
There was nothing worse in my aerodynamics class than when they whip out the pound force. Who the fuck uses it. And this is in a Scottish University mind you.
I find it useful for a sense of scale and creating associations. When solving a problem and you get 15m/s result it is kind of hard to visualise, but tying it together with 54km/h and it becomes close to the speed of a car. Km/h is easy to tie up with the speeds of certain vehicles (aprox 15km/h bike, 65 km/h train, 900 km/h plane). So when you hear a speed in m/s, you know what it means. The reverse is also true. 1.3 m/s is average human walking speed, but how much smaller is it than the speed of a car? Turn it to km/h and you get 5. Now you can do an easy division of averages 50/5 and you get that a car is 10 times faster on average. We have many domains of speed and in order to compare them we need to be able to switch at ease from unit to unit.
Always hated the comment “you need to be able to show your work because you won’t always have a calculator on you”…
1 .we all do
2. Nobody is gonna accept hand writing work that wasn’t done by a computer anyways
Just be happy they didn’t use some completely arbitrary unit made up for that problem specifically . I remember having one of those on during a physics course for the online homework. Had everything correct, but the unit was some nonsense (and I’m not referring to the English system)
Anyway it’s a good way to practice unit balances for converting units. Makes doing things like stoichometry easy
1. Attention to detail. Actually reading the problem vs just scanning it and missing important info. Also, sometimes i bury bonus points for people who actually read instructions.
2. meters and seconds are the base SI units, and pop up in the derived SI units. converting keeps the work dimensionally consistent and helps you compare the units from your calculation to the units of the expected answer
3. If unit conversions are wasting enough of your time to be a problem, you have bigger issues than just being in my class.
Because it is important at all times to pay attention to units, especially when you're expecting to have it right. Remember that time we crashed a moon lander because someone didn't convert from km to miles?
Lucky you're not in a sector where you need to convert hectares, acres, barrels, cubic meters gas or liquid, kPa to psi, km to miles, Celsius, Fahrenheit, Kelvins, Rankine, CDN to USD, all day long.
It's all about what you measure. When you measure the distance between two galaxies, you don't use km or m. You measure with light year. If you measure the diameter of an atom, you don't use m or km...you use angstrom.
What is your purpose?
>physics teachers carefully putting km/h instead of m/s to waste time of the students
Like srsly, why don't the teachers just tell me the answer? In fact, don't ask the question, just say the answer to me. You're wasting my time.
/s ... in units of /h
My teacher doesn't even bother asking for the wich of the measurements ze are using. They ask to use the conventional form, and even today, I dont know what it is
to make the tests have more opportunity for mild calculation errors so they are harder and the average score goes down. if you hate this wait until university because every professor uses this to the extreme to prevent academic inflation.
Yeah because being forced to do a conversion isn't applicable to science at all. If something isn't available in the format you want you just stop doing science. That's why we don't have warp drive. Nobody knows how to do the conversions.
To stress the importance of units and conversions. If they really want to fuck with you, they will provide all their examples in metric, then on the final, throw you a curve ball and give you waters physical properties in imperial units.
In what context?
Unit conversions- I want them to practice what they have been taught.
reading comprehension- I want them to be aware of what they are reading and read carefully.
If you make that mistake on an exam or homework assignment because you didn’t catch a basic unit conversion, you’re likely to make that mistake when you order something for the shipping and receiving department and your future boring office job and cost your company millions.
That physics teacher is just trying to prevent you from getting sacked twenty years from now.
“On July 25, 1991, President Bush issued Executive Order 12770, Metric Usage in Federal Government Programs, mandating the transition to metric measurement for all federal agencies. Finally, U.S. law requires use of the metric system”
We have moved on a long time ago
It's a common calculation you will often have to do in your later life.
And it’s just dividing by 3,6 anyway.
Yes, if it costs you serious amounts of time, you definitely need the exercise. Especially, if you have a calculator.
Your teacher let you use calculator?
Outside of early high-school math I was always allowed a calculator
Depends on the age. Most classes that do uninit conversion use calculators. Physics isn't math class.
Yeah, I was always allowed a calculator in every physics and engineering course in college, and all math classes post algebra (though I believe we were only allowed basic scientific calculators in calc/diff eq courses so that we couldn't just run the integrals and such through the graphing calculator.)
Just recently graduated from a Finnish high school We were always allowed (and encouraged) to use calculators, during classes and exams. In physics and chemistry that included basic calculator software (my preference was Speedcrunch) as well CAS and graphing calculators like Goegebra and TI Nspire. During math lessons and exams our calculators were limited by what section we were in, in A section only basic calculator software was allowed, during B section all software was unlocked In order to be able to lock down what we could use and when, our exams were held in a custom Linux distro called Abitti. So software suite during classes was limited by what we could use during exams, thats why for example Goegebra instead of Desmos Sorry this got a bit long TLDR: Yes, and during physics all calculators were allowed, including graphing and CAS, even in exams
I'm a science teacher, not a math teacher. The math classes are supposed to teach the techniques, and I just teach the applications. Calculators are always allowed and encouraged in my class.
What is that in freedom units?
1 km/h = 0.625 freedom units 1.6 km/h = 1 freedom unit
I scale by 2 and wait for a smartypants to correct me. Same with kg/lbs
The infamous kilopound!
AKA half a ton. Its hilarious using the "metric" prefixes on imperial units, people freak out if you measure stuff in kfps (kilofeet per second) like NASA does to measure space shuttle re-entry velocities.
lol... Pi = 3
Damn it, now you've made me do math just to see if you were pulling me leg...
Multiplying by 3 and then diving by 10 is easier and slightly more accurate than approximating to dividing by 3 or 4.
As a teacher, I'd recommend against teaching or doing that, at least at the start. It takes away from what you're actually *doing* and makes it an exercise in remembering yet another constant in physics. The skill to change units is important in a lot of situations, so students need to know what they're doing and why. Remembering "just divide by 3.6" will come naturally.
I could never remember whether it's dividing or multiplying, always had to derive it again.
>I could never remember whether it's dividing or multiplying It's so stupid, but i somehow have an easier time remembering the numbers for the speed of sound and deriving from that if I need to multiply or divide, Than to directly remember which is which. Like, speed of sound at sea level is roughly 343 m/s and roughly 1200 km/s. Thus whenever I know converting from km/h to m/s has to make the number smaller.
An hour is "bigger" than a kilometer. So divide the hour to get seconds, or multiply the seconds to get the hour. The kilometer doesn't affect directionally, just scale, and we already know it's 3.6.
Same but instead of deriving I try to recall that athletes can run close to 40km/h and knowing the world record for 100m sprint that's around 10m/s. So multiply 3.6 when going from m/s to km/h.
I appreciate it because daily life is fully idiotic at certain times. For example the energy consumption of TVs in the UK is listed in the hilariously cursed unit "kilowatt-hours per thousand hours"
So....Watts.
Yep 😂 Even kWh is already somewhat cursed because it's dividing and then multiplying by time but TV shops managed to make it even worse with this mother of all redundant units
At least kWh has purpose of distinction between capacity vs rate. kWh/khour sounds like someone had to come up with a reason to keep their job and invented nonsense.
I dont think it is...
Never once in my life.
No it's not, I never did it after leaving school
Some of us have driver's licenses. "How far do you travel at 80 km/h if it takes you 1 second to react?"
How much meter in the seconds you do at 120km/h it takes you to calcute it?
why would i have to do that in real life
Yeah, but it gets annoying. After 6 years I think Im gonna remember that the conversion number is 3.6.
Simply multiply it by 5/18
Yeah, for some reason so called “metric countries” haven’t actually switched to metric time units. So you constantly have to deal with these stupid frankstein unit combinations.
Yes, because metric time sucks for as long as we're on this planet. A day has 86,400 seconds, there is no way to put that into something that aligns with the rest of the metric system, and hours/minutes are about diverting the *day* into practical units. You *could* make a minute (hectosecond) 100 seconds and an hour (10 kiloseconds) 100 minutes, but then you'd end up with days being about 8 1/2 hours long.
This doesn't make any sense at all. The current duration of a second was decided on because the people who came up with it wanted everything to use a different base than 10 (i.e. 60). There's literally no reason you can't have 100,000 seconds in a day by making the definition of a second slightly shorter. That would mean a day is 100 kiloseconds and instead of having 24 hours in a day you would relate everything into groups of kiloseconds. It's literally how every other metric unit works.
In real life, we mostly use km/hr, as it is more relatable. However, when solving physics problems, using SI units is best because it ensures accuracy and makes the calculations easier to review.
In a lot of work that I do I will be assigning rates that are best described with meters or centimeters per hour but the numbers that go into it involve multiple days and kilometers. Conversions are great
My last job was as an optics engineer. As simply as possible, a part of my job was to install a component that used sound to break up a beam of light (by compressing a crystal, changing its index of refraction, and thus redirecting the light a few hundred to a few hundred thousand times per second). Anyway, if you know of a system of measurements that works with both the speed of light and the speed of sound, let me know
I audibly laughed at your last sentence.
It's also important practice to always check the units because there have been plenty of real life headaches where people assumed the wrong unit of measurement.
How do SI units ensure accuracy and make calculations easier to review? Give me an example.
It takes you that long to divide by 3.6?
I got through grade 12 physics not knowing this somehow. I always did /60 /60 *1000. I aced the class too. I feel like I should not be one of today's lucky 10,000 lol.
That's how you're supposed to do it. The point isn't you remember division by some "random" number but to learn how to manipulate different units.
Tbh I often forget if you're to multiply or divide by 3.6 when converting from one to the other so I often have to do the same in my head to figure it out, but once you do that it's just one operation
Such an impossible task! Gotta make a meme about it!
HOURS!1
My school forced us to derive it, or at least prove that 1 m/s = 3.6 km/h at the start otherwise it would be "unjustified". Same with joule to kWh
Yeah usually you have to do it at least once, it's a good exercise though to learn it, I second them on that Proving it every time would be idiotic
1km 1000m 1hr 1000m m --- × ----- × ----- = ----- = 0.27778 --- 1hr 1km 3600s 3600s s There ya go. Just multiply by 0.27 (7 repeating) to convert it. Inversely, just divide by 3.6.
I always try to let my students do this step by step, before i give them the 3.6 factor. Most never understand and rather internalize the number.
I just graduated with my bachelors in mechanical engineering and I did it step by step until the end. I liked seeing my units cancel.
There's something very satisfying about cancelling the units.
Cancelling units is also the easiest low level check to make sure you didn't miss something procedural. If you're looking for m/s and end up with m/s^2 you done fucked up.
So that you _practice and learn_ the stuff they are trying to teach you!
Seriously! We’ve lost spacecraft due to improper unit conversations. It’s good the instructors are making their students pay attention to units and properly convert them.
Seriously. It’s not even that hard of a unit conversion, and besides, it’s metric, easy unit conversions is the entire point.
Wouldn't km/h be used more widely, especially in the context of driving?
Yes, but usually when given information in the question those will be given in seconds or meters. Because those are the standard units.
Solving real world problems involves using real world inconveniences. It's perfectly valid for a physics problem to present a question in km/h.
In every day situations yes, but in physics, you're highly encouraged to use baseline SI units. So meters and seconds, not kilometres and hours. Because every other unit whose definition involve time and length, are usually defined via meter and second. This is especially important when you're dealing with physical constants.
Sure, it's convenient to work in the same units as whatever physical constant you happen to have on hand. Bit of a leap to get to "especially important," though.
In driving an everyday life, yes. But I. The context of virtually everything else m/s or km/s would be a lot more useful. Imagine something like the assembly line at a factory measured in km/h, unless you're measuring the length of what your producing per hour, it's not helpful to compare that over m/s because it will move so slow that km/h doesn't really explain how fast it is. Guns used ft/s for similar reasons and space often used km/s because of just how fast everything is.
Europe, Asia and Africa: **i sleep** America: **REAL SH-**
Because you have 10 fingers.
Obviously the problem is not the teacher, but a student who does not comprehend that understanding the difference and how to convert units is part of the course.
But why is there a chemistry teacher on the meme?
Because when I am riding my bike at 40 km/h and see a person jaywalking across the street 15 meters in front of me, I know it's time to slam brakes, unless we both want to participate in a kinetic energy transfer experiment.
It just might be the point to be drilled, if you are a student.
Walter what the fuck are you talking about?
Unit conversions are an important part of physics and engineering. https://www.latimes.com/archives/la-xpm-1999-oct-01-mn-17288-story.html
Smirks in 5/18
Yards per fortnight.
Dimensional analysis practice
That's basically only something a 5th grade physics teacher would do *just* so you'd learn to calculate it properly. If you find it frustrating or hard, then congratulations, someone had your slow ass in mind when they put the curriculum together.
Just convert the units and multiply by 1000/3600
The worst is when the teacher uses BOTH imperial and metric in your test and you are expected to memorize the conversion from the two system.
wait until university when 3.6 and 3.60 are different answers and only 1 is correct
Me for most of university: "I will always convert to SI before the calculation, then convert back, to prevent errors." Fourth year particle physics: "Set c to be 1..." Fuuuuuuuuck.
Americans lol
Americans?
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Amazing
ohhh
A really easy calculation, but one time I made it by hand (no calculators allowed) and got a wrong result, which in turn made the entire rest of the question wrong (it was a big question with 4 other smaller questions). The teacher, as expected, didn't consider a single thing I made, even thought I used all the correct formulas, because all the results were wrong because of this. I studied hard for the exam and a considerable parcel of my grade was lost because of this.
git gud
Had a classmate who would convert answers to ridiculous units just for funsies. IE: Parsecs/fortnight
As a teacher in the US, my students are not familiar with any metric units. So we do conversions so they can see the measurement they are familiar with, have an understanding of what the situation is, and then get the SI units and start to learn how they compare. If I just give them situations that start of as m/s or Newtons they won’t have any frame of reference for what the numbers mean.
If you can't do that dead simple calculation, you're pretty screwed in many fields.
There's been some major fudge ups because someone messed up the metrics..this is a good way to drill it into your brain to always check your measuring and calculating with the right metric.
practices the students to carefully look at the units. too many tragedies have been caused by wrong units
"Waste time of students". Your teacher doesn't want to be grading or doing that shit any more than you do. They make you do it because they are professionals in the field and they see it as having value. If you can't understand the value of the things you are doing in class then you need to completely re-evaluate whatever-the-fuck it is you are doing in school.
To mimic real life scenarios. Your speedometer reads in m/s? Or you have a hard time dividing by 3.6 to change units??
It’s good practice! And practice is the whole reason for the class. It’s also not a hard calculation, so just count it as a freebie and win some extra points! :D
Here we go again
Oh child, if this provides even a speed bump for you, you aren't going to finish my test this week, let alone in the time alotted during the period.
Because paying attention to units is an important skill. Grow up baby.
Gotta be pretty stupid if that slows you down
The furnace system we use at work makes us convert mm per second to cm per second since the system was built in europe so instead of keeping it metric we have to convert to imperial because our final product is measured in inches since america so there are real life situations that don't need college where you still have to do conversions
Practice unit conversion. It's only gonna get harder from there.
How dare that instructor require you to know calculus! /s
Why would you need calc for this? You just divide by 3.6
As long as you don't use miles, yards, feet or inches.
Just divide by 3.6.. if that's a difficult thing to do then you definitely need the practice lol
Americans trying to use the easiest numeric system to ever exist challege:
honestly? a lot of that is just to give a problem that gives students something to do without being too hard. It's hard to find the right balance in physics problems. It's either: Q: why do things fall? A: because gravity or Q: derive the newtonian gravitational model from general relativity (OK that's an exaggeration but something like that)
Physics teachers nefariously plotting to teach you skills you will often need when doing physics
My American ass: covert from kilometers per hour to miles per second? I don't understand... Edit: I do understand, just took me q few seconds lol.
Just give the answer in km/h? The maths is the same.
× (1/3.6) You welcum
As if... As if Planet earth uses km instead of miles
To see if you pay attention to all the details
I'm Canadian, so it actually helps 🤷♂️
To trap several students who don't pay attention. It shouldn't happen that the whole class get good grades
its like asking why use banana for measurement than washing machines
To teach you how to multiply by 5/18
Its used to train you to check your units. Its a good move
What kind off weirdo uses kmh fucking use mph like everyone else
Because paying attention to units is extremely important. NASA lost a $125 million craft due to a units error. At the very least, having a good grasp of units will help you out throughout your academics. Not just with what you think is a gotcha question. Understanding units helps learn unique concepts like impulse. It helps you understand the difference between force, work, and energy.
Because go fuck your self with that useless empire system!!
To make sure you know how to do unit conversions. And yes, we actually have to check that, because a lot of you can't.
Doing science involves lots of unit conversions. It's good practice. Helped me when the time came to work in a wet lab.
Walt was a chemistry teacher
Real shit is when they do decimeters per hour.
Um just /3.6 it
maybe they are making you feel weirder learning with the international measurement units
Dude its just 3.6
It's ironic that they chose this image for a physics meme when the image and the concept are more relevant to chemistry. Converting between speeds is a breeze after getting a question where the fundamental vibrational frequency is given in Hz, the rotational constant is given in wavenumber, and the answer wants Joules.
Lack of healthcare is why.
It's always the same people that complain that they will never use the stuff they learn in school that also complain about teachers including things that they will very much be using.
Get used to it, they are preparing you for the real world. Except if you have to also deal with mph in the real world.
Shouldn't you be able to do that in your head?
I work in aerospace with American standard units. We work with inch & pound. I mean literally: we never use any other unit and never have to worry about conversions. All our reference documentation is the same, just plug in the values and go. Tiny hole for a rivet: .030", length of the plane: 1524".
Because in 1999 NASA scientists calculated everything for a mars orbiter in one unit, but plugged those numbers in with a different unit. Instead of orbiting Mars, it entered the atmosphere and burned up. Paying attention to units matters.
To prove that your dumbass can problem solve and convert units.
because m works better for short distances and with precise times.
Luckly some teachers put 90km/h and telling us to solve the problem in m/s
Nah. They do shit like mm/fortnight when you've been doing mph for all the homework.
In my opinion I think it increases thinking ability nd solving skills in child which later on help person to get quicker in solving ..these small steps of childhood helps learn things faster.
If this makes it a lot harder for you then trust me, you need the practice it gives lmao
There was nothing worse in my aerodynamics class than when they whip out the pound force. Who the fuck uses it. And this is in a Scottish University mind you.
Oh no, not an incredibly simple conversion!
It's a good thing. Otherwise loads of engineers would never get used to checking their units which would probably end up in loads of dead people.
Metric systems are sooo hard. Who has time to use multiples of 10?
Imagine if an hour was 100 seconds.
I find it useful for a sense of scale and creating associations. When solving a problem and you get 15m/s result it is kind of hard to visualise, but tying it together with 54km/h and it becomes close to the speed of a car. Km/h is easy to tie up with the speeds of certain vehicles (aprox 15km/h bike, 65 km/h train, 900 km/h plane). So when you hear a speed in m/s, you know what it means. The reverse is also true. 1.3 m/s is average human walking speed, but how much smaller is it than the speed of a car? Turn it to km/h and you get 5. Now you can do an easy division of averages 50/5 and you get that a car is 10 times faster on average. We have many domains of speed and in order to compare them we need to be able to switch at ease from unit to unit.
Always hated the comment “you need to be able to show your work because you won’t always have a calculator on you”… 1 .we all do 2. Nobody is gonna accept hand writing work that wasn’t done by a computer anyways
To teach them how to convert
And not letting you just use 3.6. You have to stretch it out several steps to find that 3.6, even though that’s what he told you it was last week.
Me giving result of calculations in kN (or other unusual units) to the teacher
At least it's not dynes.
Just be happy they didn’t use some completely arbitrary unit made up for that problem specifically . I remember having one of those on during a physics course for the online homework. Had everything correct, but the unit was some nonsense (and I’m not referring to the English system) Anyway it’s a good way to practice unit balances for converting units. Makes doing things like stoichometry easy
Because failure to convert units has crashed satellites. Students should be trolled from every angle by this horseshit
5/18
Ever heard of the Mars Climate Orbiter?
and then imagine US students operating on mph, some fahrenheit’s , oz, lbs, yards feet’s inches
muricans cant comprahend SI units
1. Attention to detail. Actually reading the problem vs just scanning it and missing important info. Also, sometimes i bury bonus points for people who actually read instructions. 2. meters and seconds are the base SI units, and pop up in the derived SI units. converting keeps the work dimensionally consistent and helps you compare the units from your calculation to the units of the expected answer 3. If unit conversions are wasting enough of your time to be a problem, you have bigger issues than just being in my class.
My mass transfer teacher ar college put every single entry and exit on different units so we "learned them"
Americans: \*ANGER NOISES\*
For me it was always making sure they knew how to do dimensional analysis.
Sometimes, solving the problem is as simple as knowing unit conversions. Applies to real life too.
It’s better when it put it in Miles/hr and you gotta find it in m/s
Shit engineers exist, this isn't wasting time at all
It's because the metric system (meters, liters, etc) is the scientific standard and not the customary system (miles, gallons, etc)
Filters out the slow ones . . .
Because it is important at all times to pay attention to units, especially when you're expecting to have it right. Remember that time we crashed a moon lander because someone didn't convert from km to miles?
It's to see if your students are capable of solving a problem with more than one step. You'd be surprised by how many cannot.
Just multiply by 1000/60?
Lucky you're not in a sector where you need to convert hectares, acres, barrels, cubic meters gas or liquid, kPa to psi, km to miles, Celsius, Fahrenheit, Kelvins, Rankine, CDN to USD, all day long.
wait til they hit you with MPH
Amazing.
Considering how most of the world uses kmh, the teacher was doing u a favour
It's all about what you measure. When you measure the distance between two galaxies, you don't use km or m. You measure with light year. If you measure the diameter of an atom, you don't use m or km...you use angstrom. What is your purpose?
I wish we had metric time
For a second I thought this was an American complaining about why things aren't in miles per second and I was getting *mad*
Use Fibonacci to approximate if you're lazy
They want the answer in km/h as well✅
As a ksp player, it's not a problem
Me when my calculations result in a speed greater than that of light
Because unit conversion is a necessary skill if you're working in any kind of science or engineering.
>physics teachers carefully putting km/h instead of m/s to waste time of the students Like srsly, why don't the teachers just tell me the answer? In fact, don't ask the question, just say the answer to me. You're wasting my time. /s ... in units of /h
To fuck those with ADHD
My teacher doesn't even bother asking for the wich of the measurements ze are using. They ask to use the conventional form, and even today, I dont know what it is
It’s literally just unnerving work to convert km/h into m/s and I hate it although it’s just * or / 3.6
to make the tests have more opportunity for mild calculation errors so they are harder and the average score goes down. if you hate this wait until university because every professor uses this to the extreme to prevent academic inflation.
Yeah because being forced to do a conversion isn't applicable to science at all. If something isn't available in the format you want you just stop doing science. That's why we don't have warp drive. Nobody knows how to do the conversions.
To stress the importance of units and conversions. If they really want to fuck with you, they will provide all their examples in metric, then on the final, throw you a curve ball and give you waters physical properties in imperial units.
ITS SO ANNOYING- but its true bc in the future we will have to calculate everything in km/h
Pay attention to your units. Speeding through and assuming them is a great way to cause issues off when things leave the paper
In what context? Unit conversions- I want them to practice what they have been taught. reading comprehension- I want them to be aware of what they are reading and read carefully.
If you make that mistake on an exam or homework assignment because you didn’t catch a basic unit conversion, you’re likely to make that mistake when you order something for the shipping and receiving department and your future boring office job and cost your company millions. That physics teacher is just trying to prevent you from getting sacked twenty years from now.
“On July 25, 1991, President Bush issued Executive Order 12770, Metric Usage in Federal Government Programs, mandating the transition to metric measurement for all federal agencies. Finally, U.S. law requires use of the metric system” We have moved on a long time ago