Elastic or not? Billiard ball colliding with another

[aeromat]

Homework Statement

Billiard ball with mass 0.155kg moves with a velocity of 12.5m/s towards a stationary billiard ball. Assume they both have identical masses. The first billiard ball moves off at an angle of 29.7° clockwise after hitting the stationary one, with a velocity of 9.56m/s. Determine whether the collision was elastic?

Homework Equations

The Attempt at a Solution

Ok the main thing I need to ask is this: is the energy conserved independent for each dimension, in this case, x and y have diff. kinetic energy conservations?

 

[rock.freak667]

What you'd need to do is find the velocity of the second ball and then check to see if KE before is the same as KE after.

 

[ashishsinghal]

Ok the main thing I need to ask is this: is the energy conserved independent for each dimension, in this case, x and y have diff. kinetic energy conservations?

Kinetic energy is conserved irrespective of dimension if it is an elastic collision