This video accompanies the handout titled Force Probe Measuring Friction Force (available below). The goal is to understand why the friction graph has the shape that it does and understand the underlying cause of each type of friction.
After viewing this tutorial, you should be able to answer the following:
1. What is the mechanism that allows the friction value to grow when pulling progressively harder on a stationary object?
2. What is the irony about calling the object stationary in this example (think back to the "immovable" concrete block)?
3. What is the mechanism that makes the friction value have a single value when the object is moving in contrast to a range of values when the object is at rest?
4. Define a) kinetic friction and b) static friction.