1. Spectacular Science Presentation by Daniel Riedinger Teacher Reseda HS Police Magnet

2. Friction What is it Opposes motion empirical laws of friction first investigated more than five hundred years ago by Leonardo da Vinci

3. Types of Friction Sliding Friction: friction produced when two solid objects slide over each other. Rolling Friction: friction produced when an object rolls over a surface. Fluid Friction: friction produced when an object moves through a fluid.

4. Is Friction a Good Thing or a Bad Thing?

5. What Affects Friction Surface type and weight Force from friction/weight of object = A constant number f / N = µ the coefficient of friction f = µ N What about surface area? Friction is independent of surface area

6. Tornadoes Whirling funnel shaped cyclone Common on the great plains during spring Up to 300 mph winds

8. Tornadoes Tornados are the smallest, most violent, and shortest lived severe storm. When a thunderstorm encounters high altitude, horizontal winds, a tornado can be formed. These winds can cause the rising air in the thunderstorm to start rotating. A narrow funnel shaped, rapidly spinning extension may develop in the cloud.

9. Tornados generally cover a path of about 100m wide, destroying everything in their path. The tremendous speeds of the winds in a tornado are responsible for the destruction they cause. The falling of debris when a home is destroyed or being struck by flying objects causes most deaths and injuries. It is very important to find cover in a low place.

10. Worst Tornado March 18, 1925 Started in Missouri, ended in Indiana Forward speed was a record setting 73mph For over 100 miles, the path was about three quarters of a mile wide 2027 injured, 695 dead