# Momentum and Collisions

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1. Dec 6, 2011

### jer_hall99

1. The problem statement, all variables and given/known data
A moderate force will break an egg. However, an egg dropped on the road or sidewalk usually breaks, while one dropped on the grass usually does not break. This difference is because for the egg dropped on the grass:

A. the change in momentum is greater
B. the change in momentum is less
C. the time interval for stopping is greater
D. the time interval for stopping is less
E. the change in velocity is less

2. Relevant equations

vf=(m1v1+m2v2)/(m1+m2)

3. The attempt at a solution
My thoughts are that the answer is "E" because the change in velocity is less because when the egg comes in contact with the grass, a perfectly inelastic collision occurs where if the egg hits the sidewalk, it is only an inelastic equation.
Are my thoughts right, or is it a different answer?

2. Dec 6, 2011

### grzz

What does Newton's 2nd law say?

3. Dec 6, 2011

### jer_hall99

The acceleration a of an object is directly proportional to the net force acting on it and inversely proportional to its mass. That doesn't help me too much... Maybe I'm not putting two and two together. Is the answer "E" then?

4. Dec 6, 2011

### grzz

Newton's 2nd law: 'the rate of change of momentum is directly proportional to the applied force and takes place in the direction of this force'.