Force and Acceleration 2

A mass m=1kg (the red one in the drawing) is attached to a massless string. The string can move freely over a massless pulley. At the other end of the string a mass M (the grey one) is hanging. At t=0 to mass m is released, while the string is stretched to its full length.
The graph on the right side of the screen shows the velocity of m as a function of time.

• Describe the motion of m and M.
• Write down Newton's eqution of motion for m and for M.
• Solve these equations and find from the graph the acceleration of gravity on the earth, hte moon and on Jupiter.