You and your friends are doing physics experiments on a frozen pond that serves as a frictionless, horizontal surface. Sam, with mass 80.0 kg, is given a push and slides eastward. Abigail, with mass 50.0 kg, is sent sliding northward. They collide, and after the collision Sam is moving at 37.0° north of east with a speed of 6.00 m}s and Abigail is moving at 23.0° south of east with a speed of 9.00 m/s.
(a) What was the speed of each person before the collision?
(b) By how much did the total kinetic energy of the two people decrease during the collision?