WARM-UP & HW Check:
A. What is the formula for momentum? (don't forget vector symbols)
B. What's the formula for impulse?
C. https://www.youtube.com/watch?v=fdeH6Ksedwk
Impulse is the change in momentum (Δp).
1. Is the impulse when the brick hits the table the same or different as the brick hitting the foam?
When our video presenter jumps from the table, he begins falling.
2. Does his momentum increase, remain constant, or decrease?
3. Does he want to experience a strong force when he lands? Why/why not?
4. How does he protect himself upon landing?
5. Why are running shoes helpful for our feet?
CLASSWORK:
We will rotate through today's lab.
Half of you will work on practice problems: pg 251 56-61
Answers:
56: 0.013s
57: a) -14kg*m/s b)-3.2 x 104 N
58: 74 kg*m/s 1.0 x 101 m/s
59:
60:
Half of you will work on today's lab.
We will switch at 1:15
STILL STRUGGLING WITH our online lab? This might help...
Reminder: It's due by Wed for full credit.
So, in Part 1, you're pushing one cart into a stationary second cart. For both those carts, their initial velocity is the velocity they have prior to the collision. One cart has a velocity around 0.2 to 0.4m/s, and the other cart is at 0m/s. Here's how you measure velocity: VIDEO LINK Since the carts stick, you have to add their masses for the 'departing' portion of the problem.
In other collisions, you may encounter a situation where the cart you pushed probably stopped, and the only other cart started moving. The velocities of the carts after the collisions would be your final velocities. One would be 0m/s (or very close to zero - some of the carts started moving backwards....) and the other would be somewhere around 0.2-0.4m/s.
Here's a video showing this: https://www.youtube.com/watch?v=IQTpaYJHZNchttps://www.youtube.com/watch?v=IQTpaYJHZNc
For your lab write-up, it should look like this: VIDEO LINK
Let me know if you have any other questions...
Mr. A
Homework:
Complete Practice&HW problems from Day 64.
Online Lab due Wednesday
#Goals: SWBAT...
1. Solve conservation of momentum problems.
WARM-UP:
1. Use Example Problem 3 on pg 240 to solve problem 19 (10 minutes)
CLASSWORK:
1. HW Questions?
2. Try problem #21 on pg 240
3. Quiz On Tuesday!
Try problem #20 on pg 240
4. For Next Class: Predict the Outcome...
http://www.physicsclassroom.com/mmedia/momentum/2di.cfm
5. Mythbusters:
https://www.youtube.com/watch?v=r8E5dUnLmh4
6. Complete the Practice Quiz for 5 extra credit points:
Josh stops his 2000g skateboard, and then tries to jump off. Josh, who weighs 80.kg, jumps forwards with a velocity of
2.0m/s. What is the resulting velocity of his skateboard in m/s?
1. Read CH9 pg 241 on Two Dimensional Collisions (5 minutes)
3. NOTES: Review Example Problem 4 on pg 242
A 1325-kg car, C, moving north at 27.0 m/s, collides with a 2165-kg car, D, moving east at 11.0 m/s. The two cars are stuck together. In what direction and with what speed do they move after the collision?
(10 minutes)
3. Practice Problems: pg 243 22-25 (45 minutes)
Tutoring available after school Mon, Tues, and Wed until 4:30. Lunch almost every day.
HOMEWORK:
Study for your quiz