DAY 51

Goals: SWBAT...

1. Momentum - Is It Conserved?

Warm-Up (5min):

1. A clown is on the ice rink with a large medicine ball. If the clown throws the ball forward, then he is set into backwards motion with the same momentum as the ball's forward momentum. What would happen to the clown if he goes through the motion of throwing the ball without actually letting go of it? Explain.
2. Dale, Mel, and Shanelle are astronauts on a spaceship. They each have the same mass and the same strength. Dale and Mel decide to play catch with Shanelle, intending to throw her back and forth between them. Dale throws Shanelle to Mel and the game begins. Describe the motion of Dale, Mel and Shanelle as the game continues. If we assume that each throw involves the same amount of push, then how many throws will the game last?

CLASSWORK

1. #051A: Is momentum conserved? Conclusion

• complete collecting data for #050B
  • Stuck? Here are two videos to help you through the process.
  • Measuring displacement and time
  • Filling in the chart
• Complete the conclusion. Also, answer the following questions at the end of your conclusion:
• 1. Did your initial and final momenta match exactly? If they didn't, you made an error (which is okay).
• 2. What do you think caused your error?
• 3. What effect did your error have on your data?

2. #051B: Momentum Conservation Practice Problems

solutions for the practice problems are here: LINK

1. 1. When fighting fires, a firefighter must use great caution to hold a hose that emits large amounts of water at high speeds. Why would such a task be difficult?
2. A large truck and a Volkswagen have a head-on collision.
   1. a. Which vehicle experiences the greatest force of impact?
   2. b. Which vehicle experiences the greatest impulse?
   3. c. Which vehicle experiences the greatest momentum change?
   4. d. Which vehicle experiences the greatest acceleration?
3. If a ball is projected upward from the ground with ten units of momentum, what is the momentum of recoil of the Earth? ____________ Do we feel this? Explain.
4. If a 5-kg bowling ball is projected upward with a velocity of 2.0 m/s, then what is the recoil velocity of the Earth (mass = 6.0 x 10²⁴ kg).
5. A 120 kg lineman moving west at 2 m/s tackles an 80 kg football fullback moving east at 8 m/s. After the collision, both players move east at 2 m/s. Draw a vector diagram in which the before- and after-collision momenta of each player is represented by a momentum vector. Label the magnitude of each momentum vector.
6. In an effort to exact the most severe capital punishment upon a rather unpopular prisoner, the execution team at the Dark Ages Penitentiary search for a bullet that is ten times as massive as the rifle itself. What type of individual would want to fire a rifle that holds a bullet that is ten times more massive than the rifle? Explain.
7. A baseball player holds a bat loosely and bunts a ball. Express your understanding of momentum conservation by filling in the tables below.

At Home Learning (HW)

1. You should have finished the Lad in class today. I'll be collecting it Thursday

2. Take notes/answer edpuzzle questions on the following:

a. (6:46) Introduction to Elastic and Inelastic Collisions - EDpuzzle

b. (5:39) Introductory Conservation of Momentum Explosion Problem Demonstration - EDpuzzle

3. QUIZ tomorrow :) Momentum and Impulse. Review by completing the questions in 051B (solutions for the practice problems are here: LINK), and by reviewing the problems we solved in 049A and 049B