1. The force that one object exerts on another when 2 objects are rubbed together Eventually, the force of friction will cause objects to stop movement Starting on Text page 324

2. Types of Friction Explain where you see friction happening in each picture.

3. Describe the 2 factors that determine the strength of friction Types of surfaces Sneakers running on sand? Sneakers running on track? Strength of force pushing together Rub cold hands together lightly? Rub cold hands together forcefully?

4. Sliding- occurs when solid surfaces slide over each other Rolling- needs less force than sliding friciton and occurs when objects roll over other objects Fluid- occurs when objects move through fluid like air or water

5. Describe the difference

6. Words to Know Friction Sliding friction Rolling friction Fluid friction Gravity Free Fall Projectile Air Resistance Terminal Velocity Workbook pages 113-119