WARM-UP
Quiz Today. You need a sheet of paper. You have three minutes to prep...
CLASSWORK
You can work on two things today. Collecting data from the online lab (due tuesday) or....
collecting data from our in-class lab (due thursday). You choose...
1. Collecting Data to Measure Momentum
How would you collect v data from this video? LINK
2. Online Lab Updates
Rough draft due today. Complete labs, correct or not, get 10/10.
Final Draft due Tuesday next week.
STILL STRUGGLING WITH our online lab? This might help...
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
I made youtube versions of the cart videos.
Clip #1 https://www.youtube.com/watch?v=T_7PxutPFFw
Clip #2 https://www.youtube.com/watch?v=4yM-k1Zbvs8
Clip #3 https://www.youtube.com/watch?v=4CbUtTSIkHk
Clip #4 https://youtu.be/5qBqTK1mcX8
Clip #5 https://youtu.be/zTnf6f0y52I
Labs are due Tuesday via Google Docs by 11:59pm
#Goals: SWBAT...
1. Solve conservation of momentum problems.
2. Prepare for Monday's CH 9 Exam :-)
WARM-UP:
1. Find the resultant for the diagram shown on the whiteboard to the right of the projector screen.
2. Calculate the angle theta from the given info (again, to the right of the whiteboard)
CLASSWORK:
1. Test is next class. Prepare yourself.
2. Review of Example Problem 4
3. Try a few problems
Pg 243 22
Answer 36.6* North of West (you can also write this as 53.3* West of North). Final Velocity is 11.2m/s.
5. Practice test for HW:
pg 250-254
Problems 33; 34, 38, 40, 49; 56; 59; 61; 68; 72; 74; 80
Answer:
33: Yes, provided the velocity of the bullet is high enough (bullets have very small mass)
34: Impulses are the same, but in opposite directions. For b), the the force is related to the amount of time the ball has to accelerate. Think about it.... email jgalexander@gmail.com if you get stuck.
38: An isolated system has _____ external forces acting on it.
40: All of the momentum from the cue is transferred to the the 8-ball
49: positive direction, stationary, negative direction
56: 0.013s
59: a. 2.0x104kgm/s
b. 1.3x103N
61: -6.0x101N
68: a: -7.1 kgm/s
b: -1.4x104N
72: a: -2.00x102kgm/s
b: -4.0x103N
c: 4.1x102 kg
d: No
e: because you would kill your child if you didn't have them in a child-seat
74: a: Before: mc=5.0g mD=10.0g vCi=20.0cm/s vDi=10.0cm/s
After: mc=5.0g mD=10.0g vCf=8.0cm/s vDf=?
b: pCi=1.0x10-3kgm/s
pDi=1.0x10-3kgm/s
c: 4.0x10-4kgm/s
d: 1.6x10-3kgm/s
e: 16cm/s
80: 11m/s
Tutoring available after school Mon, Tues, and Wed until 4:30. Lunch almost every day.
HOMEWORK:
1. Complete the practice problems
2. More practice for extra credit: #81, 85, 90
3. Bring a sheet of notes for the exam