Prerequisite: Read sections 5.1,2.

People are often surprised at the photo to the right and ask if the ball was fully inflated. In fact, it was. Even before the ball had moved only slightly from the tee, the ball was greatly deformed by the kicker's toe. Explained in terms of Newton's laws, the mass (inertia) of the ball is one of the things that influences its acceleration. For a given force, the acceleration is inversely proportional to the mass (Newton's 2nd Law). In the short time that the collision had lasted, the acceleration of the ball wasn't great enough for the ball as a whole to have moved very far.

The video clips below will teach you about the concept of inertia and Newton's First Law. After viewing the clips, there's a WebAssign assessment to do.