Physics Demonstrations & Labs

1. Physics Demonstrations & Labs Demonstrations and labs to teach force and motion will be showcased. Tricks of the trade will be shared as multiple teachers display their favorite activities for teaching these topics. Katie Beck, Laura Henriques, Meredith Ashbran, Andrew Baker, Carey Baxter, Louis Coleman, David Eisenberg, David Ronquillo, Natalie Young – CSULB faculty & students CSTA’s Science Education Conference Pasadena, CA October 23, 2011 HANDOUTS AVAILABLE ON THE CSTA CONFERENCE SITE This workshop is presented by students enrolled in PHYS490 at CSULB as part of the PhysTEC project. Find out more about PhysTEC at physicsatthebeach.com

2. Introduction – Katie & Laura • PhysTEC at CSULB • Opportunities for you to get involved • Monthly Demo Days (2nd Thursday of the month, 4:30 in HSCI277 at CSULB) • Physics Teacher Open House Events – each semester for you (and 2 of your students!) • Monthly newsletter • PHYS490 – Content specific physics teaching course

3. Book and Paper Drop- David E. Question 1: If a book and a piece of paper are dropped from the same height at the same time which will fall faster? Question 2: If a book is placed on top of a piece of paper both are dropped at the same time which will fall faster? Question 3: If a piece of paper is placed on top of a book both are dropped at the same time which will fall faster? Question 4: If a piece of paper is placed on its edge on top of a book both are dropped at the same time which will fall faster?

4. Newton’s First Law - Natalie • Diving pens • Flicking pennies • Diving eggs

5. Diving Pens • Materials: bottle, embroidery hoop, pen with a flat bottom • Balance hoop on bottle • Balance pen on the hoop (over bottle mouth) • Quickly remove the hoop & the pen will go into the bottle • Notes to teachers….. http://www.youtube.com/watch?v=uOSBC0SXVR4

6. Diving Eggs • Place a pie tin on 1-3 beakers of water (1/2 filled) so that the edge of the pie tin extends beyond the edge of the table • Place toilet paper tubes directly above the beaker(s) • Put a raw egg horizontally onto each tube (as shown in next slide) • Quickly remove the tray (a broom helps!) • Notes to teacher….. • http://www.youtube.com/watch?v=sQRZsDbR6qM

8. Egg into a Sheet - Carey • Have four students help you hold a bed sheet. They should hold it vertically and taut with one student at each corner. The students on the bottom corners need to create a small “gutter” to catch the egg. • Get a student to throw a raw egg at the sheet as hard as possible. It won’t break! • Be sure that the sheet is not held directly in front of anything rigid - like a wall! http://www.youtube.com/watch?v=7RSUjxiZnME

9. Meredith • Dynamics Carts to demonstrate Newton’s 2nd and 3rd Laws

10. Roll for your Grade - Katie • Turn a simple common textbook problem into a hair raising event

11. Circular Motion & misconceptions - Laura • Circular motion requires a net force - direction is always changing. • What provides the force to keep an object moving in a circle? • What happens if that force is removed? What happens to a marble that is rolling around the edge of a plate when it comes to the end? What are the forces involved here?

12. Rotating Bucket of Water - David R. Background • Vectors, Velocity, and Acceleration. Knowing that the velocity and acceleration of an object are defined, both in terms of their magnitude and direction, and that a change in the direction of velocity with respect to time will result in non-zero acceleration, allows us to determine the magnitude and direction of the centripetal force on an object undergoing a curved motion. Inertia. Materials • 3 1⁄4 inch x 8 inch wooden board with four small holes drilled at its four corners. Two shoelaces have each of their ends passed through two of the holes on the board. The lengths of the my shoelaces that are passed though the holes are measured to be equal at a workable distance from the board and tied together at a node point. A plastic cup filled about 1⁄2 way with water.

13. Penny in a Balloon- Carey • Set-up: uninflated balloon, penny. • Related concepts: friction, centripetal force, Newton's First and Third Laws, circular motion.

14. Angular Momentum - Andrew • What happens to the angular momentum of the tennis ball as the radius gets smaller? Materials: tennis ball shoelace/string PVC pipe.

15. A tour of angular Momentum - Louis Presentation 1 3 2 Bicycle Wheel Member of the Audience Rotating Stool While standing on the stool, have a member of the audience come up and spin the tire. As the tire is spinning, flip the tire so that it’s axis of rotation is Perpendicular to the earth. Flip the tire completely over and watch as you rotate the opposite direction of the tire.

16. How it works? External angular momentum is initially applied to the system (wheel, me and stool) by the audience member spinning the wheel. When the audience member lets go there is zero unbalanced torque on the system and the angular momentum is constant. Momentum is transferred from the bike wheel to me exemplified by Newton’s Third Law of motion, which states that the force acting on one object is equal and opposite the force reacting by that object, if the two objects are collinear. So, if I hold the wheel along its axis of rotation a force is applied perpendicular to my arm span and a torque spinning me the opposite direction of the wheel manifest. Since angular momentum is conserved and my moment of inertia is greater, my angular momentum is equal but opposite to that of the wheel but my magnitudal rate of spin is slower. If I hold the bike wheel so that its force on me is parallel to my arm, torque does not manifest and I do not rotate.

17. Extras…..

18. PHET simulations If you aren’t familiar with PHET you are in for a treat! Visit http://phet.colorado.edu/ Click Play with Sims then Physics then Motion Particularly good ones for force & motion are: Moving Man, Skate park, and projectile motion. All are free, they download so you don’t need web access at school and if you scroll down on the page you’ll find teacher developed lesson plans.

19. A force has both direction & magnitude. Staple rubber band to index card. Unfold a paperclip. Hang it on the bottom of the rubber band. Attach various weights to the bottom of the paperclip. Note the resting position for each. • Forces are vectors. To completely describe a force you must state how big it is and the direction in which it is acting. • We can use simple force detectors to measure and/or detect forces. 1 2 3 Simple force detector or accelerometer. Plexiglass casing with colored water sandwiched between. Available commercially.

20. Force Detectors • The shape of the water indicates the direction of the force. • The water has inertia and it remains at rest (or in motion) relative to the container allowing us to see the direction of the force.

21. Other Force Detectors/Accelerometers Cork in a bottle, fishing bob in a plastic container of water, or helium balloon in a car. Katie has her kids carry around “Bob” for a week. No net force, the cork is at rest. Note the position of the cork & the shape of the water. Net force to the right!

22. For more information • www.physicsatthebeach.com for information about our PhysTEC grant. • To contact lead presenters: Katie Beck – kbeck@ggusd.net Laura Henriques – Laura.Henriques@csulb.edu