69. (a) We use conservation of mechanical energy to find the speed of either ball after it has fallen a distance h. The initial kinetic energy is zero, the initial gravitational potential energy is M gh, the final kinetic energy is 122Mv, and the final potential energy is zero. ThusMghMv=122and vgh=2.The collision of the ball of Mwith the floor is an elastic collision of a light object with a stationary massive object. The velocity of the light object reverses direction without change in magnitude. After the collision, the ball is traveling upward with a speed of 2gh. The ball of mass mis traveling downward with the same speed. We use Eq. 9-75 to find an expression for the velocity of the ball of mass Mafter the collision: 2232.Mf
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 05/17/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.