Question

A car accelerates at a costant rate from 15m/s to 25m/s while it travels a distance of 125m. how long does it take to achieve the fina lspeed?

Answer 1

a = (25 - 15) / t = 10 / t acceleration of car

S = V0 t + 1/2 * 10 / t * t^2 distance traveled

125 = 15 t + 5 * t = 20 t

t = 6.25 sec (note a = 10 / t = 1.6 m/s^2)

Check:

S = V0 * t + 1/2 a * t^2

S = 15 * t + 1/2 * 1.6 * t ^2

S = 15 * 6.25 + .8 * 6.25^2 = 93.75 + 31.25 = 125