# Elastic Collision in Deep Space

1. Jun 4, 2014

### Rookie

Hello! I need help with this physics problem, I've some what attempted it and I need some feedback. ANY help would be awesome!

1. The problem statement, all variables and given/known data
Two objects (A and B) of equal mass, undergo an elastic collision in deep space. Initially, B is at rest and A approaches at velocity v. The duration of contact is 2 seconds.

(a) What is the velocity of object A after the collision (final velocity)?
(b) What is the final velocity of B?
(c) At what time is the kinetic energy of the two object system a minimum?
(d) What has the kinetic energy been converted to?

2. Relevant equations

3. The attempt at a solution
(a) A velocity is 0.
(b) B velocity is equal to A initial velocity, v.
(c) I don't know :|
(d) Momentum (not sure).

2. Jun 4, 2014

### Lok

Hi Rookie,

a,b) Your answers seem intuitive and while they could be right you need to use equations to validate your claims.

c) What is the sequence of events of the elastic collision? This can help you understand the question.
d) What can Kinetic Energy convert into?

3. Jun 4, 2014

### Rookie

c) Would it be at the middle of the collision, 1 second? Where minimum there is no relative motion, I think?
d) Sound energy and thermal energy?

4. Jun 4, 2014

### Lok

c) That is where it should be in ideal conditions.
d) Well those are true but do not happen in space during an assumed ideal elastic collision. What else can store energy in this setup?

5. Jun 4, 2014

### Rookie

Ahh is it internal energy?