Ok, this seems fairly straight forward, but I can't get my head around it. You have an object (0.3kg) with a vertical (up; positive) velocity of 10 m/s. This object's velocity is supported by a rising piston. Once the piston stops it's movement, how do you determine whether the object has enough momentum to overcome gravity, and jump? What would be the "Force" required to stop this jump? OK, thanks in advance.