An object of mass m155 kg moving at 49 ms strikes a

Question

Question: An object of mass m1=5.5 kg moving at 4.9 m/s strikes a stationary second object of unknown mass. After an elastic collision, the first object is observed moving at 3.43 m/s at an angle of -47° with respect to the original line of motion.

Part A: What is the energy of the second object?

Part B: What is the magnitude of the second object's momentum after the collision?

Part C: At what angle did the second ball move relative to the direction of the first ball's initial motion? (Give answer in degrees)

Part D: What is the mass of the second ball?

I want help to find the magnitude of the second object's momentum after the collision.