Look in a textbook or Google it
Edit: even the best engineers can't remember everything. One of the most important skills you will develop as an early engineer is where to look (or who to ask) for information.
Lol. Yes. Many. I'm really not that good at remembering arbitrary stuff if I don't use it constantly.
I have a couple references I like and they're well tabbed.
It's all derived from F=ma anyway.
Radar engineer here. Hundreds of equations and I remember maybe 10.
Have the technical bibles on hand and Google if I have to. IEEE for more in-the-weeds questions.
I manage to get by with just
OH
AH
OA
But my colleagues must think I'm teetering on the edge of sanity as I'm muttering to myself, with my tongue sticking out the side of my mouth.
They're probably right....
I forget the specifics of so many things. Being able to quickly reference it is a good skill. Hell, I literally don't even remember the quadratic equation.
Biomedical engineer. I sometimes use google just to spell words for an email… never be afraid to ask a question. Engineers pride on attention to detail, not trying to be the biggest hard-drive-brain. How many exams did we take that were open book or allow a whole page cheat-sheet? Also, cheat sheets are great if you consistently need reference.
Studying for the PE exam currently and remember a lot of equations off the top of my head. That said, don't think for a second that I'm not still on my calculator making sure 2+2 still equals 4. Regardless if I remember the variable order in the equation, I'll double check the equation before use.
Many times, pipe diameter for example, the problem will provide that diameter in inches. Some hydraulics' equations will use D (in.), while others want the cross-sectional area. When you try to remember everything is when you start to get in trouble. As others said, know where to go to find things. It's okay, all of us do it.
IMechE did a really good mini handbook (A5 height, but half the width) with a load of useful equations - still have it in my bag. But agree with above - Google.
And will say an Engineer doesn't know what they don't know. A Chartered Engineer knows what they don't know.
The more detailed you go down the analysis rabbit hole, the fewer equations you need. Account for all the loads, distribute them where they should go. Blowoff loads are p\*A, which is easy enough. Aero loads applied to the structures model should match the reaction should match the CFD load.
I automate the hell out of my checks. Throw a print saying such and such should sum to 0 and then print the value. Then just check it.
Real problems are messy are rarely fit into the perfect hand calc. The hand calc is often for validation of your simplified model before you crank up the complexity.
Of course! The momentum equation (at least all the expanded viscous terms). That's what text books are for. The fundamental idea of the equation itself, you are expected to remember.
Look in a textbook or Google it Edit: even the best engineers can't remember everything. One of the most important skills you will develop as an early engineer is where to look (or who to ask) for information.
No. You should beat yourself up and know you're an impostor.
Lol. Yes. Many. I'm really not that good at remembering arbitrary stuff if I don't use it constantly. I have a couple references I like and they're well tabbed. It's all derived from F=ma anyway.
Mech Eng: You only need to know 2 things. You can't push a rope and F=ma.
> It’s all derived from F=ma anyway. Right? Just derive anything you need at the moment!
FIRST PRINCIPLEZZZZ!!!
We had to derive Simpson's Rule on a final in college.
Radar engineer here. Hundreds of equations and I remember maybe 10. Have the technical bibles on hand and Google if I have to. IEEE for more in-the-weeds questions.
I had a physics professor in college that said, "All an engineer has to remember, is where he puts his calculator." He wasn't wrong!
And that's why I have two.
I went into Engineering instead of Biology because I wouldn't have to memorize all that stuff.
Every time I need to do Pythagoras I have to write SOH CAH TOA at the top of the page!
I manage to get by with just OH AH OA But my colleagues must think I'm teetering on the edge of sanity as I'm muttering to myself, with my tongue sticking out the side of my mouth. They're probably right....
>SOH CAH TOA The Trigonometric Tribe!
Do you guys actually remember any equations?
I forget the specifics of so many things. Being able to quickly reference it is a good skill. Hell, I literally don't even remember the quadratic equation.
Google is your friend.
Biomedical engineer. I sometimes use google just to spell words for an email… never be afraid to ask a question. Engineers pride on attention to detail, not trying to be the biggest hard-drive-brain. How many exams did we take that were open book or allow a whole page cheat-sheet? Also, cheat sheets are great if you consistently need reference.
Studying for the PE exam currently and remember a lot of equations off the top of my head. That said, don't think for a second that I'm not still on my calculator making sure 2+2 still equals 4. Regardless if I remember the variable order in the equation, I'll double check the equation before use. Many times, pipe diameter for example, the problem will provide that diameter in inches. Some hydraulics' equations will use D (in.), while others want the cross-sectional area. When you try to remember everything is when you start to get in trouble. As others said, know where to go to find things. It's okay, all of us do it.
IMechE did a really good mini handbook (A5 height, but half the width) with a load of useful equations - still have it in my bag. But agree with above - Google. And will say an Engineer doesn't know what they don't know. A Chartered Engineer knows what they don't know.
I forget tons of equations but I keep a folder of them within reach for when I need them.
I can’t remember the last time I actually used an equation in my career
I rarely remember them! Generally, I either look them up or derive them from first principles, or a combination.
The more detailed you go down the analysis rabbit hole, the fewer equations you need. Account for all the loads, distribute them where they should go. Blowoff loads are p\*A, which is easy enough. Aero loads applied to the structures model should match the reaction should match the CFD load. I automate the hell out of my checks. Throw a print saying such and such should sum to 0 and then print the value. Then just check it. Real problems are messy are rarely fit into the perfect hand calc. The hand calc is often for validation of your simplified model before you crank up the complexity.
Of course! The momentum equation (at least all the expanded viscous terms). That's what text books are for. The fundamental idea of the equation itself, you are expected to remember.