Train Physics Problem

1. Feb 6, 2010

Physuph

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

A given train can stop in t seconds when it is running at its maximum speed. The train driver sees a car stalled at an intersection that is d1 meters ahead of the train, and instantly pulls the brake starting while at its maximum speed. The train reaches the intersection u seconds later, but does not hit the car because the car darts out of the way at the last moment. The train travels d2 more meters before it comes to a complete stop.

Supposing that the train's acceleration through all this is constant, how far was the train from the car? In other words, what is d1? (in terms of t, u and d2)

2. Relevant equations

v=v0 + at
vav= (1/2)(v0+v)
etc...

3. The attempt at a solution

I have a bunch of equations and I can't seem to put them together to find the solution.

2. Feb 7, 2010

Redbelly98

Staff Emeritus
Think in terms of a, Δv, and Δt, and see if you can set up some equations.