1. Physics 11 Force Diagrams Mr. Jean

2. The plan: Video clip of the day Force Diagrams Friction Friction Practice Questions

3. Net Forces: The existence of an unbalanced force for a given situation can be quickly realized by looking at the free-body diagram for that situation.

4. Brightstorm Videos: Net Forces: http://www.brightstorm.com/science/physic s/newtons-laws-of-motion/net-force- resultant-force/ http://www.brightstorm.com/science/physic s/newtons-laws-of-motion/net-force- resultant-force/ http://www.youtube.com/watch?v=AFnoBr hOR4Uhttp://www.youtube.com/watch?v=AFnoBr hOR4U

5. Consider the following forces:

6. Consider the following:

7. Solutions:

8. Determine the Net Forces:

9. Solutions:

10. Determine the acceleration if the object had a mass of 2kg:

11. Solutions:

12. Practice Questions: P. 144 –Question #5 & #6 Upcoming items: –Rocket Design Day #1 Thursday Research & Introduction –Quest Assignment #4 due next Sunday

13. Rocket Design Information:

21. The Engines:

22. Rocket Build Goals: Nose Cone test Wing test Parachute Test Engine Size Test

23. Nose Cone Test: A proper nose cone must fit inside the rocket fuselage. –The fit should be snug –Nose cone should detach from body when an individual quickly blows air through the body. Do not have your parachute in when testing this!

24. Wing Test: In order to test the strength of the wings. A individual should be able to hold the entire rocket by one wing. –If the wing becomes unglued, falls off or structurally fails this rocket is not suitable for flight.

25. Parachute Test: Take a 100g weight and attach parachute to it. Drop from ceiling with parachute fully open. The parachute should guide the weight softly to the ground without horizontal displacement. –Common Failures Parachute lines break Parachute causes horizontal motion Issues with parachute design

26. Engine Test Part #1: Engine should have a snug fit to the inside of the fuselage. –There MUST be a point where the engine can not go past. However there must remain hollow space to allow the parachute deployment charge to function correctly. –Engines are NOT to be glued into the rocket.

27. Engine Test Part #2 Engines should be secured to make sure that when deployment charge explodes it does not fire the engine out the back of the model. –Rockets MUST HAVE some type of engine harness preventing the engine from falling out the bottom end.