# Homework Help: Car Crash Physics Involving Skid Marks

1. Jul 11, 2012

### guppster

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

Two vehicles crash at an intersection
Mass of vehicle one: 1858kg
Mass of vehicle two: 2865Kg

Vehicle one was headed North
Vehicle two was headed East

The two vehicles stuck together in a t-bone fashion and the two vehicles left the intersection stuck together, moving at an angle of [N67E].

The vehicles left 40.0m skid marks behind.

15.334m of skid marks were on wet asphalt with a friction coefficient of 0.8.

24.6666m of skid marks were on dirt with a friction coefficient of 0.5.

Determine the initial velocity (before the crash) of vehicle one.

I am instructed to use kinematics and dynamics to solve this problem.

2. Relevant equations

Vf = Vi + 2ad

Fg = mg = weight = normal force

fk = µkFN

3. The attempt at a solution

I created a free body diagram but do not know how to approach the problem, any help is appreciated.
I have also searched this website for similar answers but non applied to my problem

Last edited: Jul 11, 2012
2. Jul 12, 2012