Editing Inclined Plane (section)

===Short Explanation===
When something rolls down a hill or slope, we know that it will accelerate because of the force of gravity. However, we don't usually think about how ''much'' it will accelerate, which depends on two things: the shape that is rolling, and how hollow the shape is. When we rolled the solid spheres, we see that they all accelerated at the same rate, even though they were made of different materials. This is because they are the ''same shape'', and so they will accelerate the same down a slope! We saw the same thing happen with the solid cylinders, but then we saw that a hollow cylinder rolls slower than a solid cylinder. This is because a hollow shape has a different center of mass than a filled shape. The ''Center of Mass'' of an object is a spot in space where the mass of the object is centered around. The center of mass doesn't have to be at a spot in the object's mass. For a hollow shape, the center of mass is in the hollow area, so it has to transfer any motion along the outside, which takes longer. The filled cylinder can transfer motion through its center, since the center of mass is within the object's mass. It is faster to go through the center than to go around the outside, so the solid cylinder will always roll faster! The solid cylinder, however, rolls slower than the solid sphere. This is because every spot on the outside of a sphere is the same distance from its center, while every spot on a cylinder is '''not''' the same distance from its center. A solid sphere will always roll faster down a slope than a solid cylinder!