Question

A force scale is attached to a stack of books lying on a flat table. 1.What happens to the size of the static frictional force as you begin to pull on the force scale? 2.What happens to the stack of the books if the applied force exceeds the maximum static frictional force? 3.What is the minimum size for the static frictional force, and under what conditions will the minimum static frictional force be observed? 4.What type of friction acts when the books are at rest but a force is exerted?

Answer 1

1. When you pull on the force scale, an opposite and equal reaction is also induced. This is the static frictional force. So when you begin to pull, the static frictional force gradually increases.

2. If it exceeds the maximum static frictional force, then the stack of backs begins to move. Then the static frictional force is converted to kinetic frictional force.

3. The minimum static frictional force is the least amount of force when you pull the force scale. Technically, you do not need to pull on it to achieve the minimum.

4. The type of friction is called the static frictional force. The term used is static because the object is at rest even though forces are exerted on it.