Question

A car starting from rest passes two successive milestones A and B that are 250 m apart. It takes 60 s to pass A and another 60 s to pass from A to B. Find the velocities of the car when it passes milestone A and milestone B. Assume that the acceleration of the car is uniform 

Answer 1

$x=\frac{at^2}2,$

$x+s=\frac{a(2t)^2}2=2at^2,$

$s=\frac{3at^2}2,$

$a=\frac{2s}{3t^2}=0.046~\frac m{s^2},$

$v_1=at=2 .8~\frac ms,$

$v_2=2at=5.6~\frac ms .$