DAY 86
ESSENTIAL QUESTION: Momentum - Is It Conserved?
Goals: SWBAT...
1. To determine if momentum is conserved during explosions
Warm-Up 86 (4min):
A 0.5-kg ball moving at 5 m/s strikes a wall and rebounds in the opposite direction with a speed of 2 m/s. If the impulse occurs for a time duration of 0.01 s, then the average force (magnitude only) acting upon the ball is ____ Newtons. Solve, then choose the correct answer below.
CLASSWORK
1. Monday Review
- fish catch
- notes
- practice problems
2. #086A: Exploding Carts Interactive
- Similar to the Fish Catch, today you'll be collecting data, looking for patterns, finding direct or inverse proportionality, and coming up with a rule (equation) to describe the carts behavior. To do that, you will analyze explosions which propel two stationary carts in opposite directions.
- Copy all data tables into your notes
- Collect data
- Answer all questions (1-9)
- Questions/Handout LINK: https://www.physicsclassroom.com/getattachment/Physics-Interactives/Momentum-and-Collisions/Exploding-Carts/Exploding-Carts-Activity/ExplodingCarts.pdf?ext=.pdf
- Interactive LINK: https://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Exploding-Carts/Exploding-Carts-Interactive
If you didn't finish yesterday's classwork (reposted below), do so today
2. #085B: Momentum Conservation Practice Problems
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?
A large truck and a Volkswagen have a head-on collision.
a. Which vehicle experiences the greatest force of impact?
b. Which vehicle experiences the greatest impulse?
c. Which vehicle experiences the greatest momentum change?
d. Which vehicle experiences the greatest acceleration?
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.
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).
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.
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.
A baseball player holds a bat loosely and bunts a ball. Express your understanding of momentum conservation by filling in the tables below.
Learning at Home/HW
- Complete the CW from today
Goals: SWBAT...
1. Momentum - Is It Conserved?
2. To prove that momentum is conserved
Warm-Up (5min):
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.
Dale, Mel, and Shanelle are astronauts outside 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. #086A: Conservation of Momentum Notes
- Take notes
LINK: https://www.physicsclassroom.com/class/momentum/Lesson-2/Momentum-Conservation-Principle
2. #086B: Momentum Conservation Practice Problems
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?
A large truck and a Volkswagen have a head-on collision.
a. Which vehicle experiences the greatest force of impact?
b. Which vehicle experiences the greatest impulse?
c. Which vehicle experiences the greatest momentum change?
d. Which vehicle experiences the greatest acceleration?
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.
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).
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.
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.
A baseball player holds a bat loosely and bunts a ball. Express your understanding of momentum conservation by filling in the tables below.
3. 086C: Review for tomorrow
Learning at Home/HW
- Complete the CW from today
WARM-UP:
1 & 2: See board, left side
CLASSWORK:
1. #086A: HW Review
2. #086B: Electric fields LINK
3. #086C: Calculating Charge
4. #086D: Drawing Electric Field Lines & Ranking Charge Strength
ANNOUNCEMENTS
1. Friction Rods Activity is now due Monday
2. Complete the Handout on Electric Fields and Electric Field Lines (2 sides) (extra copies are on the seat next to my computer, or links to the handouts are on Day 86). Due Monday. Note: There will be a video posted here on Friday (LINK) covering how to complete the table in problem number 9.
3. Practice problems from Friday (today in class) are due Monday.
4. Extra Credit Opportunities: Due by Wednesday
A. 20 classwork points: Complete all four electric field charts correctly. Incorrect = zero points LINK
B. 10 homework points: Complete the Polarization activity (print out the handout, or recreate the drawing on a piece of paper) here: LINK
HOMEWORK
1. Watch Mr. P's (Flipping Physics) video (in HD, so you can see the board) on Electric Potential Energy. Keep in mind, this is very similar to Gravitational Potential Energy, so look for connections between the two concepts. Answer the following questions while watching...(questions are in chronological order)
1. In terms of energy, what happens to the green medicine ball when Mr. P drops it?
2. In terms of energy, what happens to the positively charged tennis ball when Mr. P drops it?
3. Which force causes Gravitational Potential Energy? Which causes Electric Potential Energy?
4. List the four types of mechanical energy (keep in mind, what we called energy of a "spring", he calls "elastic". Same meaning though)
5. For Gravitational Potential Energy, we use the equation PEg=mgh, where h is the vertical height, because the gravitational field is vertical. For Electric Potential Energy, what equation do we use, and what is the special rule for the displacement?
6. Copy the derivation of the units for PEele along with Mr. P. What are the units for all energies (PEele included)?