1. The problem statement, all variables and given/known data Consider the thought experiment shown in the figure below. A tunnel is constructed from the North Pole to the South Pole of the Earth and a cylinder is placed within the tunnel at the South Pole. Study the influence of the gravitational force of the Earth on the cylinder. Describe the motion of the cylinder fully. 2. Relevant equations Well since it says study the influence of gravitational force I'm assuming that Formula will be used. Maybe their are other formula's that I should use but I'm currently unsure 3. The attempt at a solution At first glance at this problem I thought that this would be a simple harmonic motion. With the cylinder oscillating from one end to other end and eventually comming to rest near the centre of the earth. Not sure if this is the correct approach. This is not really a homework assignment because it's optional but I'm going to at least try to attempt this and I need some help. If anyone has some reading material related to this that would be really helpful. I don't care if it's a book or magizine or some internet article I'm a little pressed for time and I would appreciate any kind of help. Thanks.