You and your friends are doing physics experiments on a frozen pond that serves as a frictionless, horizontal surface. Sam, with mass 72.0 kg, is given a push and slides eastward. Abigail, with mass 54.0 kg, is sent sliding northward. They collide, and after the collision Sam is moving at 36.0 degrees north of east with a speed of 5.80 m/s and Abigail is moving at 15.0 degrees south of east with a speed of 8.80 m/s.
What was the speed of each person before the collision?
By how much did the total kinetic energy of the two people decrease during the collision?
The momentum on initial x = momentum on final x
The momentum on initial y = momentum on final y
m1 = Sam, m2 = Abby
mv = momentum
The Attempt at a Solution
(72.0 kg)(unknown) + (54.0 kg)(0 m/s) = (72.0 kg)(5.80cos36)+(54.0 kg)(8.80 cos15)
(72.0 kg)(0)+(54.0 kg)(unknown) = (72.0 kg)(5.80sin36)+(54 kg)(8.80sin15)
Sam = 11.067 m/s
Abby = 6.823 m/s
I also need help for Part B.
Am I approaching this problem correctly? Thanks.