PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Linear Momentum · Linear Momentum
Problem
Two ice-skaters glide on a straight, frictionless stretch of ice and collide head-on. Skater A has mass 4kg and is moving east at 10ms−1; skater B has mass 2kg and is moving west at 15ms−1. They cling together after collision.
(i) Find the magnitude and direction of their common velocity just after they stick together.
(ii) Calculate the loss of kinetic energy in the collision and express it as a percentage of the initial kinetic energy.
(iii) Keeping the mass values unchanged, determine the speed (magnitude only) that skater B must have before impact so that the pair comes to rest immediately after they cling together.