Physics of Impulse

Today, you will be figuring the impulse of three different systems using videos.  In each, you will need to determine the mass of a ball in kg, so you will need to use the logger pro and a force probe as a scale.  Attach a cup to the force scale, weigh it, drop in the ball, weigh it, and then subtract the difference.  Convert that value to kg using  F=ma      Show work on one of the trials.


Trial 1:  What impulse is transferred from a pool cue to the cue ball during a hit?


Trial 2:  What impulse is transferred from the cue ball to the ball that is hit?


Trial 3:  What impulse is transferred from a ball to the bumper as it is hit.


Analzye the three videos on logger pro to determine the change in velocity.   The time it takes for the collision  will show on the dot-analysis.   For each printed trail, show me the calculation for the change in velocity (v(final) - v(initial), the change in momentum (m* change in velocity), the impulse value, and the Force applied.

11/28/12

Today, you will be looking at two simulations.  First, go to

http://www.squadron13.com/games/collision/collision.htm 

Try

• head on collisions
• glancing blows, 
• a collision between a heavy ball and a heavy ball, 
• a collision between heavy ball and a light ball, 
• a collision between two balls of medium mass.

For each one of these, describe what happens BEFORE and AFTER the collision by writing a sentence and making a diagram.  Each person should do this individually.  

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Next, go to http://www.physicsclassroom.com/class/momentum/u4l1b.cfm  and work through problems 1 through 7 at the bottom of the page.  The answer is listed, but I want to see your diagram of BEFORE and AFTER, as well as your work.  Each person should do this individually.  

Tomorrow, we will be trying to collect information on IMPULSE using the pool tables.  What is the critical information to know.

Hand in your work at the end of the hour.

1d collisions on Pool Tables

Use your phone or a flip video to make the videos.   You may need to convert them, so use a video converter.

You will need to upload each of these items to your Google Docs account.   Make sure it is in an .avi or .wmv (Windows Live Movie Maker) format and is less than 50 mb.

1. Make a 30-60 second video that shows you and your pool table, it's dimensions, and it's gravity feed system.   Take a picture from above showing the break of the balls.
2. Create a one ball collision with a bumper using a video feed.
4. Create a two ball video between the ball and a second ball that illustrates 1-d momentum.
5. Create a two ball video between the ball and a second ball that illustrates 1-d momentum where the pool ball stops.
6. Analyze #2-5 using logger pro and the movie feature. Make certain you scale your picture.  Here's a tutorial if you need it.
7. Print your data.

I

Using Google Sketchup for a Project

Part of this project of a creating a pool table involves scaling a model using Google Sketchup, a 3D modeling tool.

You can start with a series of Google Tutorials--I like this one, but there is an entire channel devoted to Sketchup tutorials at http://www.youtube.com/user/SketchUpVideo





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This activity is adapted from High Tech High

You will be building a table top pool table.
Requirements

The Detailed Sketch must:
-- Be scaled-down from a full size pool table
-- Be no bigger than 65 cm * 130 cm
-- Be drawn on the computer (I would suggest Google Sketch)
-- Represent the ball return system that is gravity fed (not simply pockets)

The Pool Table must:
-- Include handmade billiard balls (golf balls allowed), cue sticks, & racking triangle
-- Be functional   (You may make ONE modification---having 4 ball holes instead of 6 ball holes)

The Ball Return System must:
-- Gather ALL the billiard balls in one area
-- Be easily accessible by the players
-- Be seamlessly integrated with the pool table

Step one: Make a materials list (cardboard is able to be used, plywood is perhaps better), assign roles, and create a sketch of your design (please submit the sketch to me via email)
Step two: Create your pool table by Monday, 11/19 and bring to class
Step three: Notes and Ideas



Momentum ideas

11/12/2012 Veterans Day and Momentum

First 45 minutes:   Practice Assessment

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http://phet.colorado.edu/files/activities/3324/PhET_Collision_Lab.doc

11/9/2012

Finish the Barbie writeups.


5 question quiz on Monday (sorry) on net forces horizontally and vertically.


CHAPTER REFLECTION

Bungie Barbie

Set up the equipment, attaching a Barbie on a cord to the force probe.  Connect an accelerometer to Barbie and her harness. Remember that you need to tell the Logger Pro what type of force probe is attached...it may not do so automatically.  Place a motion sensor below Barbie on the ground. Determine Barbie's Fw, and F(net) and Fup Your calculations must be shown at the moment that Barbie is at the maximum extension of the rope going DOWNWARD. All calculations must be summarized in a table when you turn in the lab.

Procedures:
Produce as least 5 different graphs by dropping Barbie with different cords. Use the evidence to collect a rationale for the common use of rubber as a bungie cord, and whether it is supported by your data.


Print or save your graphs for each "jump". Clearly indicate which cord or material was used. Also include information such as the amount of force and the time over which the force was applied. Record any relevant observations you saw during the jump.  Hint (this works best if you upload each of the five files to a Google Doc folder, and then share down to your individual machine)

Calculate the Fup on Barbie and her g-force for each jump using a printed sketch of the graph and data from your trials.  This must be accompanied by a free body diagram.

Individual WRITEUP (5 to 8 paragraphs, plus tables)

• Describe the ideal harness for a bungie jumper so that net force is distributed across the barbie. This should be based on data you gathered when Barbie parachuted, your seatbelt harness, and this lab.  A picture may be helpful here.

• Explain how the total time for the Barbie to stop jumping can affect a force distribution. (Think carefully: F=ma, but a = change in velocity/change in time)

• Based on your data, is it possible to argue that there is a better material for a bungie jump than rubber? Why or why not?
• Your seatbelt lab, your parachute jump, and the bungie jump all allowed you to gather g-force acceleration data.  Create a table of g-force information and tell me which is the safest situation:  the Barbie bumper crash, the Barbie parachuting, or the Barbie Bungie jumping?   

• What do these labs tell you about extreme sports?

• What questions arose in the lab? What information have you found?

Parachute Barbie

Today you will need to complete the Barbie parachute jump three times today.
Measure the time it takes to drop the Barbie to the ground three times, using a stopwatch.
Using a force probe that is connected to a Logger pro, measure the Force weight of the Barbie and chute.
Divide by 9.8 m/s/s to get Barbie and chute's mass in kg.

Take a picture of the Barbie, in its harness, AND a picture of the parachute and harness system.  Txt or email it to me, with your group member names


Reflection