Question

You and your friends are doing physics experiments on a frozen pond that serves as a frictionless, horizontal surface. Sam, with mass 72.0kg kg , is given a push and slides eastward. Abigail, with mass 54.0kg kg , is sent sliding northward. They collide, and after the collision Sam is moving at 40.0 ∘ ^\circ north of east with a speed of 6.40m/s m/s and Abigail is moving at 16.0 ∘ ^\circ south of east with a speed of 8.80m/s m/s
1)What was the speed of each person before the collision?
Sam's speed:
2)Abigail's speed:
3)By how much did the total kinetic energy of the two people decrease during the collision?