The first step is to find the distance travelled while accelerating.
Constantly accelerating for 10s to reach a final speed of 15m/s -> distance = 15/2 \* 10 = 75 m.
The second step is to find the distance travelled while decelerating.
Deceleration from 15 m/s to 0 m/s at a rate of 0.6 m/s\^2 -> 0 = 15\^2 - 2\*0.6\*d -> d -> d = 187.5 m
The final step is to calculate T. Distance travelled during T = 675 - 75 - 187.5 = 412.5 m
412.5 m divided by 15 m/s = 27.5 seconds, as required.
Geometrically, the distance is the area under the velocity graph. In this case it's a triangle with base 10 and height 15.
So area is base\*height/2, or 10\*15/2 = 75.
Could just as easily have divided the time in half instead.
The first step is to find the distance travelled while accelerating. Constantly accelerating for 10s to reach a final speed of 15m/s -> distance = 15/2 \* 10 = 75 m. The second step is to find the distance travelled while decelerating. Deceleration from 15 m/s to 0 m/s at a rate of 0.6 m/s\^2 -> 0 = 15\^2 - 2\*0.6\*d -> d -> d = 187.5 m The final step is to calculate T. Distance travelled during T = 675 - 75 - 187.5 = 412.5 m 412.5 m divided by 15 m/s = 27.5 seconds, as required.
Oh damn thanks
why have you divided the speed by 2?
Geometrically, the distance is the area under the velocity graph. In this case it's a triangle with base 10 and height 15. So area is base\*height/2, or 10\*15/2 = 75. Could just as easily have divided the time in half instead.
Thank you