# Speeder vs. Cop Acceleration

1. Sep 27, 2009

### nkallivrousis

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

A state trooper sets up a radar trap. A speeder passes the trooper and continues going at a constant speed of 40 m/s. The instant the speeder passes the trooper, the trooper accelerates at 5.0 m/s/s for 10 seconds and then continues at a constant speed. How far will the trooper travel before she catches up to the speeder?

2. Relevant equations

d=v1t+1/2at^2
d=1/2at^2

3. The attempt at a solution

I figured out the distance traveled for the first ten seconds by the police man to be 250 meters and his final velocity being 50 m/s. The speeder's distance in 10 seconds is 400 meters. Now I do not know how to find the distance that it takes for the cop to catch the speeder.

2. Sep 27, 2009

### CompuChip

So what is the relative distance between them at the moment the cop stops accelerating?
Then with their relative velocity, how long will it take the cop to cover that distance?

3. Sep 27, 2009

### nkallivrousis

The distance between the two cars would be 150 meters apart. The problem is that I do not know how to find a formula to discover the rest of the distance covered