1. Section 2: Conservation of Momentum and Explosions

2. Mable Activity Objective: Student will collide marble in various formations to predict and observe the outcome in terms of momentum
Test Performed
Prediction
Outcome
Conclusion: Please formulate a general conclusion on the marbles interaction in terms of momentum.

3. Law of conservation of Momentum
Total Initial Momentum = Total Final Momentum

4. Demonstrations Momentum Demonstrators Tennis Ball Videos:
(drop of water)
(momentum in space)
(slow mo guys soccer ball)

5. Very Important!!! For Momentum to be Conserved
1) Must be a closed system: Where the mass of the system does not change. 2) All forces on the system must be internal: where there are no external forces from outside contact or field forces. -this is considered to be an isolated system

6. Demo: Student on cart 1) What will happen to the cart if the student starts moving forward? 2) What will happen to system (student and cart) if the students suddenly stops? 3) Is it possible to calculate the moment of the system if so how? 4) Does the momentum of the system change? 5) What causes the momentum of the system to change?

7. Demo Explanation:

8. Demo: 1) Who will travel the fastest
Demo: 1) Who will travel the fastest? 2) When the line is completely stretched, which way will they budge?

9. Demo: Pass the rice bag. 1) What will happen to the system as rice bag is passed back and forth. Hint: Think of the total momentum of the system.

10. Demo: Stuck in Space
You are stuck in space so that you back is against the Earth. What can you do to turn around? Sit on a swivel chair and find out.

11. Collisions:
Sample Problem 1: Two space people collide and bounce off of each other. Find the square guys momentum:

12. Sample Problem 2: Find the velocity of the blue truck after the collision.

13. Sample Problem 3: Find the velocity of the catcher and ball

14. Sample problem 4:
A 100 kg cannon fires a 5 kg shell with a velocity of 400 m/s. If the cannon is on wheels, find its recoil velocity:

15. Sample Problem 5: Two astronauts are moving with a velocity of 25m/s and push off of each other so astronaut A has a velocity of zero. If astronaut A has a mass of 90kg and astronaut B has a mass of 100kg, find the velocity of B.

16. Go to Practice Worksheet

18. Space Shuttle Main Engine: Propulsion and Momentum

19. Converging Diverging Nozzle