Running at 2.0 m/s, Bruce, the 45.0-kg quarterback, collides with Biff, the 90.0-kg tackle, who is traveling at 7.0 m/s in the other direction. Upon
collision, Biff continues to travel forward at 1.0 m/s. How fast is Bruce
knocked backwards?

answer: point c: b. 1/2 potential, 1/2 kinetic, point a: 3/4 of its potential energy, point d or b: 3/4 potential, 1/4 kinetic

explanation: i cant explain. it's difficult to explain.

this is poiselle's equation from fluid mechanic in physics. mech eng

measure their densities same density, same sub