Hi folks,
Just a reminder. If you can, please bring a version of the game Angry Birds to class today.
Safe travels everyone!
Jim Mueller
Monday, January 9, 2017
Tuesday, January 3, 2017
Monday, January 2, 2017
1/2 Physics update and homework due 1/9
Hi folks,
This week we discussed the concept of impulse and how it relates to momentum. To investigate this further, we shot spitballs to illustrate how the time of the force affects momentum.
We also did the famous egg drop experiment where the students had to design a vehicle that kept a raw egg safe from a 15 foot drop. There were some brilliant designs!
For homework this week:
1. In your own words, describe to me what shooting spitballs has to do with impulse?
2. Use the concept of impulse to explain why it's so important to follow through when doing some sort of a sporting activity.
3. During the egg drop activity, you used several strategies to try to keep your egg from breaking. List three of those strategies and tell me what they had to do with impulse and momentum.
Also, Do the following questions. (Answers below.)
1. A Denver Bronco is running towards the end zone at 11 m/s (25mph). A Pittsburg Steeler running directly behind him at 15 m/s (34mph) tackles him and causes him to fumble directly into the hands of another Steeler who runs it back for, the final seconds, game winning touchdown!!! If the Bronco weighs 127 kg (280lbs) and the Steeler weighs 136 kg (300 lbs), what is their velocity after impact and before hitting the ground? (Use metric #'s only. Others are there for reference.) (Check answer when finished below.)
2. Two train cars are moving towards each other along a track. One has a mass of 32,000 kg and is traveling at 3.5 m/s. The other has a mass of 23,000 kg and is traveling at 5 m/s. Assuming they stick together after impact, what is their final velocity? (Check answer when finished below.)
3. Describe throwing a bowling ball down the alley and knocking down all the pins as far as momentum transfer goes. Start with holding the ball and end with the last pin falling. Extra Credit: Show me the #'s and calculations.
AND
Use this websitehttp://phet.colorado.edu/sims/collision-lab/collision-lab_en.html to complete the following questions:
Please let me know if this website doesn't work for folks. It works fine for me but I'm not sure it will work for all of you.
Phet Momentum Homework
1. Click on the Advanced tab at the top of the window.
2. Click on "One Dimension" in the box to the upper right.
3. Click on the "Momenta Diagram" button in the upper right.
4. Click on the "Show Values" button in the upper right.
5. Set the speed of ball 2 to 0 (Drag the vector arrow for ball 2 until V = 0)
6. Notice the total momentum of both balls. (In the momenta box to the lower right)
7. Click play.
(Be sure you look at the numbers for the following questions before either ball bounces off the wall. If you wish, you can turn off "Reflecting Border" in the upper right corner.
8. How does the total momentum of the system after collision, compare to the total momentum before collision?
9. Now, make both balls have a mass of 1.5. What happens to their velocity after collision?
10. How about their total momentum before and after collision how do they compare?
11. Now click "Add Ball" at the bottom. This ball should have a mass of 2 and a velocity of 0. What is the total momentum?
12 Now click play, what is the total momentum after collision?
13. Click on the "Momenta Vectors" button in the bottom right.
14. Click on remove ball so that you only have 2 on the screen.
15. Notice the momentum vectors. Look carefully at the total momentum vector.
16. Click play. After collision how does the total momentum vector change?
17. Add a ball and do it again. Notice anything about the momentum vector now?
18. Please feel free to play with this. Add balls, try two dimensions, what ever you wish.
Answers to math problems.
1. MV of Bronco + MV of Steeler = Mass of both x velocity of both
(11m/s x 127Kg) +(15m/s x 136Kg) = 263 x Vf
1397 + 2040 =263v
13.1m/s = V
2. MV of car 1 + MV of car 2 = Mass of both x velocity of both
(32,000 x 3.5) + (23,000 x -5) = 55,000 x Vf (Notice that the second speed is negative due to the opposite direction of travel. I assigned moving right as positive and moving left as negative.)
112,000 + -115000 = 55,000 Vf
-3000 = 55,000 Vf
-.06 m/s = Vf (The cars will be moving slightly to the left after impact.
This week we discussed the concept of impulse and how it relates to momentum. To investigate this further, we shot spitballs to illustrate how the time of the force affects momentum.
We also did the famous egg drop experiment where the students had to design a vehicle that kept a raw egg safe from a 15 foot drop. There were some brilliant designs!
For homework this week:
1. In your own words, describe to me what shooting spitballs has to do with impulse?
2. Use the concept of impulse to explain why it's so important to follow through when doing some sort of a sporting activity.
3. During the egg drop activity, you used several strategies to try to keep your egg from breaking. List three of those strategies and tell me what they had to do with impulse and momentum.
Also, Do the following questions. (Answers below.)
1. A Denver Bronco is running towards the end zone at 11 m/s (25mph). A Pittsburg Steeler running directly behind him at 15 m/s (34mph) tackles him and causes him to fumble directly into the hands of another Steeler who runs it back for, the final seconds, game winning touchdown!!! If the Bronco weighs 127 kg (280lbs) and the Steeler weighs 136 kg (300 lbs), what is their velocity after impact and before hitting the ground? (Use metric #'s only. Others are there for reference.) (Check answer when finished below.)
2. Two train cars are moving towards each other along a track. One has a mass of 32,000 kg and is traveling at 3.5 m/s. The other has a mass of 23,000 kg and is traveling at 5 m/s. Assuming they stick together after impact, what is their final velocity? (Check answer when finished below.)
3. Describe throwing a bowling ball down the alley and knocking down all the pins as far as momentum transfer goes. Start with holding the ball and end with the last pin falling. Extra Credit: Show me the #'s and calculations.
AND
Use this websitehttp://phet.colorado.edu/sims/collision-lab/collision-lab_en.html to complete the following questions:
Please let me know if this website doesn't work for folks. It works fine for me but I'm not sure it will work for all of you.
Phet Momentum Homework
1. Click on the Advanced tab at the top of the window.
2. Click on "One Dimension" in the box to the upper right.
3. Click on the "Momenta Diagram" button in the upper right.
4. Click on the "Show Values" button in the upper right.
5. Set the speed of ball 2 to 0 (Drag the vector arrow for ball 2 until V = 0)
6. Notice the total momentum of both balls. (In the momenta box to the lower right)
7. Click play.
(Be sure you look at the numbers for the following questions before either ball bounces off the wall. If you wish, you can turn off "Reflecting Border" in the upper right corner.
8. How does the total momentum of the system after collision, compare to the total momentum before collision?
9. Now, make both balls have a mass of 1.5. What happens to their velocity after collision?
10. How about their total momentum before and after collision how do they compare?
11. Now click "Add Ball" at the bottom. This ball should have a mass of 2 and a velocity of 0. What is the total momentum?
12 Now click play, what is the total momentum after collision?
13. Click on the "Momenta Vectors" button in the bottom right.
14. Click on remove ball so that you only have 2 on the screen.
15. Notice the momentum vectors. Look carefully at the total momentum vector.
16. Click play. After collision how does the total momentum vector change?
17. Add a ball and do it again. Notice anything about the momentum vector now?
18. Please feel free to play with this. Add balls, try two dimensions, what ever you wish.
Answers to math problems.
1. MV of Bronco + MV of Steeler = Mass of both x velocity of both
(11m/s x 127Kg) +(15m/s x 136Kg) = 263 x Vf
1397 + 2040 =263v
13.1m/s = V
2. MV of car 1 + MV of car 2 = Mass of both x velocity of both
(32,000 x 3.5) + (23,000 x -5) = 55,000 x Vf (Notice that the second speed is negative due to the opposite direction of travel. I assigned moving right as positive and moving left as negative.)
112,000 + -115000 = 55,000 Vf
-3000 = 55,000 Vf
-.06 m/s = Vf (The cars will be moving slightly to the left after impact.
Monday, December 12, 2016
Recording for 12/12
Hi folks,
I left my power cord to my camera at a different classroom so I couldn't record today's class. However, this link will take you to a video I shot last year that goes over those pesky momentum problems.
https://youtu.be/rii3Wg2QTEU
I left my power cord to my camera at a different classroom so I couldn't record today's class. However, this link will take you to a video I shot last year that goes over those pesky momentum problems.
https://youtu.be/rii3Wg2QTEU
12/12 Physics class and homework due 1/2
Hi folks,
We will be off the next two weeks for the holidays! We will be restarting class on January 2 2017!
Today we finished our lab from last week by having the students use the data they collected last week in order to predict the distance a block will move based on it's momentum.
We also worked on solving some new conservation of momentum problems.
Homework for next week is to:
Read pages 86 - 100 in the text book.
Do problems 1 - 18 on page 100.
We will be off the next two weeks for the holidays! We will be restarting class on January 2 2017!
Today we finished our lab from last week by having the students use the data they collected last week in order to predict the distance a block will move based on it's momentum.
We also worked on solving some new conservation of momentum problems.
Homework for next week is to:
Read pages 86 - 100 in the text book.
Do problems 1 - 18 on page 100.
Tuesday, December 6, 2016
Monday, December 5, 2016
12/5 Physics update and homework due 12/12
Hi folks,
Today we spent a little bit more time with free body diagrams as a review and then we moved onto the new concept of momentum. Momentum is basically how hard it is to get an object to come to a stop or to change directions. Mathematically it's mass times velocity. We took advantage of this beautiful day by doing our lab outside. The lab was seeing the effect of different masses and different velocities on momentum.
Homework due next week is :
Do the Momentum vs. distance the block moved graph.
Also,
Read pgs. 74 - 82
Do Review Questions #'s 1 - 18
Today we spent a little bit more time with free body diagrams as a review and then we moved onto the new concept of momentum. Momentum is basically how hard it is to get an object to come to a stop or to change directions. Mathematically it's mass times velocity. We took advantage of this beautiful day by doing our lab outside. The lab was seeing the effect of different masses and different velocities on momentum.
Homework due next week is :
Do the Momentum vs. distance the block moved graph.
Also,
Read pgs. 74 - 82
Do Review Questions #'s 1 - 18
Subscribe to:
Posts (Atom)