Problem 9. Two curling stones of identical mass, one red and one yellow, are involved in a glancing collision. The yellow stone is initially at rest and is struck by

the red stone moving with a speed v. After the collision, the red stone moves along a direction that makes an angle 0 with its initial direction of motion. The velocities of the two stones are perpendicular after the collision. (a) Draw the collision and determine the final speed of each stone. (b) Determine if this collision was elastic.