Which formula can be used to find the angle of the resultant vector has

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Ben (55kg) is standing on very slippery ice when junior (25kg) bumps into him. junior was moving at a speed of 8 m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision. give the answer in m/s. describe the work you did to get the answer.

The diagram shows a boulder rolling down a hill into a valley and then up the opposite hill. at which position does the boulder have the greatest kinetic energy? ab c d