A0.75-kg ball falls vertically downward from a height of 55.0 m and rebounds upward. if the ball reaches a height of 30.0 m and the contact between the ball and ground lasts 2.50 ms, what is the average force exerted on the ball by the ground?

Impuls I is given by:

where  is the change in momentum,  is the average force and t is the time.

Solve the equation for the force F:


Energy should be conserved, so the velocities will be:


Combining both equations:

where 

Iread this book last year so take this with a grain of salt.gene jumps from the tree to compete with finny due to the fact that gene is always trying to do better than finny. he is put under the grasp of peer pressure due to finny almost forcing him to do this. ever since he first jumped finny kept pressuring him to jump since he thought gene enjoyed jumping.rather than uses this answer you should probably just reread chapters 3-4

Independent variable is something that is changed in a experiment.