# Homework Help: Problem with acceleration and distance!

1. Feb 24, 2012

### efoster

1. The problem statement, all variables and given/known data
v, a1, a2 are the needed variables

A car is traveling in the +x direction with a speed of v when the driver notices a car that is stopped in front of him at distance d. In order to avoid a collision, he immediately applies the brakes resulting in an acceleration of -a1. At the same time, the parked car starts to accelerate in the +x direction with an acceleration of a2. Determine the distance d in terms of v, a1 and a2 if the cars are to just barely avoid a collision.
The only hint I have is: think about the position and velocity of each car. What is required to just barely avoid a collision.

2. Relevant equations
f=ma

3. The attempt at a solution

2. Feb 24, 2012

### PeterO

The hint is telling you provided the cars are traveling at the same speed the two cars could contact each other.

I would start by drawing velocity time graphs for the two cars - well actually the front of the travelling car and the rear of the stopped car

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook