Problem 11 VA=6 m/s 40° Problem 12 2139 (al-61 50° B vy-4 m/s A 600-g ball A is moving with a velocity of magnitude 6 m/s when it is hit as shown by a 1-kg ball B which has a velocity of magnitude 4 m/s. Knowing that the coefficient of restitution is 0.8 and assuming no friction, determine the velocity of each ball after impact. -28 A 4-lb ball B is traveling around in a circle of radius r₁ = 3 ft with a speed (8)1 6 ft/s. If the attached cord is pulled down through the hole with a constant speed v, 2 ft/s, determine the ball's speed at the instant r₂ = 2 ft. How much work has to be done to pull down the cord? Neglect friction and the size of the ball.