2. Hockey pucks A and B have masses m = 2kg and mB = 4kg and slide towards each other on ice. The ice is very smooth so friction is negligible. Below is a top view of the system before the hockey pucks collide: VA MA % B MB a) A initially slides horizontally to the right with a speed of 15m/s and B initially slides with a speed of 5m/s at an angle 0=36.87 as shown above. If the pucks stick together after colliding find the final velocity of the pucks. b) Instead of sticking together, suppose that A is stationary after the collision. What is the final velocity of B? Express your answer in terms of the speed and an angle with the horizontal. Also, calculate the change in the kinetic energy. Was the collision elastic or inelastic? c) Now suppose A has the same initial velocity as the previous parts but the initial velocity of m2 is unknown. However, we observe that after the collision A and B are stuck together and travel vertically up the page with a speed of 7.5m/s. Determine the initial momentum and initial velocity of m2.