Hi, I have been struggling with physics (SPH4U) practice question that relates to 2D collision. This is the question: Question 2:

Two hockey pucks of equal mass approach each other. Puck 1 has an initial velocity of 20.0 m/s [S 45 deg E] and puck 2 has an initial velocity of 15 m/s [S 45° W]. After the collision, the first puck is moving with a velocity of 10.0 m/s [S 45° W].


a) Determine the final velocity of the second puck. Show full calculations for each step.

b) Is this collision elastic, perfectly inelastic, or (non perfectly) inelastic? Explain your reasoning.