The figure shows a particle of mass m at a distance x from the center of a very thin cylinder of mass M and length L. The particle is outside the cylinder so, x > L/2.

A) Calculate the gravitational potential energy of these two masses. Express your answer in terms of the variables M, m, L, x, and constant G.

B) Use what you know about the relationship between force and potential energy to find the magnitude of the gravitational force on m when it is at position x. Express your answer in terms of the variables M, m, L, x, and constant G.