Basic Motion Question

[America]

Confused; A speeding motorbike travels past a stationary police car at a speed of 35 ms-1. The police car starts accelerating immediately at 4 ms-2, and keeps accelerating at this rate until it has passed the bike.

How far does the police car travel before it overtakes the motorbike?

At what time does the police car overtake the motorbike?

[nubs]

Let the distance travelled by the motorbike equal S_m and the distance travelled by the police car be S_p

So the question is asking you to find how much distance is travelled before the police car overtakes the the motorbike

When the police car is level with the motorbike, it means they've travelled the same amount of distance, doesn't it?

So you need to find where the motorbike has travelled the same amount of distance as the police car

So where S_m = S_p
Now try solving it before going on

Spoiler

Some useful equations: S=u*t for constant velocity (acceleration equals zero), where S is the displacement, u is the initial velocity and t is time
S=u*t+1/2a*t² for changing velocity (non-zero acceleration) where a equals the acceleration