Answer to Question #279862 in Mechanics | Relativity for BxJ

Question

A automobile starts from rest and is given a constant acceleration of 5 m/s². How long will it take before it attains a speed of 20 m/s?

Answer 1

$u=0m/s$

$v=20m/s$

$a=5m/s^2$

$t=?$

$v=u+at$

$20=0+5t$

$t=20/5=4s$