Homework Help: Mechanics question

1. The problem statement, all variables and given/known data

Car X moves with a constant speed of v m/s on a straight road heading towards a stationary car Y on the road. When car X is b m behind car Y, car Y starts to move with a uniform acceleration of a m/s^2 in the same direction as the direction of car X until it achieves a constant speed of v m/s . If car X did not overtake car Y, show that v<root(2ab)

2. Relevant equations



3. The attempt at a solution

I need to get started.

 

ok ,

so for car Y , usign

v^2=u^2+2as

v^2=2ab

v=root(2ab) and this is the final speed of car y

And car X did not overtake car Y , so Vy>Vx

root(2ab)>v

Is it that simple? This question has 5 marks . Thanks anyways .