Q. Two objects have an elastic collision. Before the collision they approach one another with a velocity of 4m/s. With what velocity will they be separating after the collision?
Q. You are swinging a tin can around your head in a perfectly horizontal circle of radius 4 m. (This is really not possible but we re saying it almost happens.) If you exert a force of 9 N and the mass of the can is 1 kg, with what speed is the can moving around the circle?