Part I: Discovering Inertia
Read the explanation and watch the motorcycle animation :
1. What is the law of inertia?
2. Why did the motorcyclist get thrown off of his motorcycle? Was there an external force pushing him forward?
3. A truck is traveling to the right and is carrying a ladder on its roof. When the truck slams on its brakes, the ladder will: a. stay on the truck b. slide backwards off the back of the truck c. slide forwards off the front of the truck
Watch the Truck and Ladder animation :
4. Was your prediction correct?
5. Was there an object pushing the ladder off the truck? Use physics terms to explain what happened to the ladder.
6. An airplane is flying eastward at 200 m/s when it drops a package out of the bottom. The package will land: a. behind the airplane b. directly beneath the airplane c. in front of the airplane
Watch the Airplane Animation :
7. Was your prediction correct?
8. Was there an object exerting a force to keep the package moving? Use physics terms to explain what happened to the package.
Watch the truck and ball animation and explain, using physics terms, why the ball landed in the truck.
Click on This Link. Scroll down and watch the "Giant Puffer" video.
9. If you replaced the air in the puffer and filled it instead with water, the water would not shoot out nearly as far as the air did. Use physics terms to explain why.
Part II: Free-body Diagrams
Watch the Skydiver Animation :
1. What happens to the drag force as the skydiver's velocity increases?
2. Sketch the FBD of the skydiver when he is falling at a constant velocity. (This is also called his terminal velocity.)
3. Just after opening the parachute, what is the direction of the NET force on the skydiver? What is happening to his velocity at this time?
Take the FBD quiz to test your understanding. Unless otherwise stated, there IS air resistance in all of the questions.