The Atwood Machine

Enter values for the masses of the two balls in fields "Mass1" and "Mass 2". Then hit go to see them fall. The acceleration of mass 1 is displayed. If the friction button is selected, then the mass of the pulley, which may be entered in the field "Mass 3" affects the system. If there is no friction, then the string connecting the masses slides freely over the pulley without accelerating it.