Fall 1998 Physics 7

Humphrey Maris

Date	Demonstration
9/9 W	A. Galilean incline plane. Plane at a small angle with marks spaced according to t^2. Observe ball passing marks and correlate with a ticking metronome. B. Dropping strings of beads. Beads spaced at distances n^2 from end land at equal intervals. Beads equally spaced land at times separated by decreasing increments.
9/11 F
9/14 M	A. Simultaneous two balls drop off table. One has a horizontal velocity and one falls straight. Both hit ground at same time. B. Vertical billiards. Like monkey and gun demonstration but with two balls starting at the same height. C. Monkey and gun demonstration. D. Howitzer and tunnel. Ball thrown in air and caught.
9/16 W	A. Circular motion with bubble for overhead. A liquid container is attached to the end of a pivot arm. The liquid contains a bubble, Bubble moves towards the center as liquid rotates. B. Metal strips which model the rotation of the earth. C. Centrifuge with dyes.
9/18 F	Ring with cut. A transparent ring has a short cut in it. Place on top of verhead. Ball bearing goes around the inside of the ring. When it comes to the cut, does it go straight out radially, continue in a circle, or go in a straight line?
9/21 M	A. Coin + Feather B. Water parabola. Demonstrate that the maximum range is obtained with 45 degrees. Project with an arc lamp.
9/23 W	A. Newton Scales. A spring scale with a weight attached. The scale reads in Newtons. If scale wand weight are dropped the scale reads zero. B. Blackboard Mechanics. Scales, pulleys, masses attached to blackboard. C. Inertia ball. A string hags from a support and is attached to heavy ball. Another string hangs below the ball. If one pulls slowly one the string the upper string breaks. If one pulls fast the lower string breaks. D. Cork on Rope. A cork is attached to the end of a string which passes through a tube. A weight is attached to the end of the rope. By swinging the cork around the weight can be pulled up.
9/25 F	Balance and burning string. Can record onto a videotape and then play back.
9/28 M	A. Cinder block on masonite. Pull back across floor using force scale. Shows static friction is greater than dynamic friction. One can put another block on top of the first block to show the variation of the friction force with normal reaction. B. Puck on turntable. Aluminum disk on turntable. Put puck on disk. It will slide off if it too far from the axis of rotation.
9/30 W	A. Bucket with sponge. Pour water into the bucket. Swing bucket around in a circle in a vertical plane. Explain why the water does not fall out. One can put a sponge in the bucket to hold the water. Then one can pretend to tip the water over a students head at the end of the lecture. Nothing to do with viscosity but this might be a convenient place. B. Viewgraph machine of liquid flows.
10/2 F	A. Zani mobile B. Air truck plus a firecracker between them. C. Water rocket. A bottle is half filled with water. There is a cork in the open end and a tube going to the compressed air supple. When the cork blows out the compressed air in the rocket pushes the water out the back and the rocket flies around the room.
10/5 M	A. Styrofoam wrench to illustrate center of mass motion. B. Hang an irregular object from three places to illustrate that the center of mass always lies below the point of support. Could perhaps find a large pretzel to use as the object.
10/7 W
10/9 F	1^st exam
10/12 M
10/14 W	A. Galileo pendulum. A string pendulum in which the string contacts a peg when the string moves in one direction. Mass rises to same height on either side of the string. B. Bowing ball basher. Ball hangs from a pendulum in front of professor’s nose. It is let go and if not pushed will come back exactly to the same spot.
10/16 F	A. Balls falling down three tracks emerge with the same speed after falling through equal heights. B. Racing balls. Same as A except the tracks are identical apart from a lowered section at the bottom. Which ball gets there first?
10/19 M	A. Two carts coupled together by a spring down an inclined track and bounce off magnet buffers at the end. Energy transferred to internal motion. B. Newton’s cradle demonstration. C. Track demo. Two carts bouncing off each other. D. Drop a basket ball to the ground with a tennis ball on top of it. Tennis ball bounces up to the ceiling. E. Pair of balls, one very elastic and one inelastic. Sad and happy balls. F. Red ball express.
10/21 W
10/23 F	A. Hula hoop used as a prop. B. Bike wheel with handles used as a prop.
10/26 M
10/28 W	A. Atwell’s machine with a massive pulley. B. Rod with cross beam with weights attached to is so that one can vary the moment of inertia. Rod has a three pulleys of different radii attached to it. Use as an Atwood’s machine. C. bike wheel with string attached to the edge. Pull string fast and break it. Demonstrates rotational inertia. D. Astronaut video. E. Stick plus puck F. Hinged stick plus cup plus ball G. Atwood’s again
10/30 F
11/2 M	A. Chaotic pendulum with second arm attached. B. A physical pendulum of some sort. Need to be able to vary the position of the pivot point. C. Simple pendulum of varying length.
11/4 W	A. Wheel with small axle rolling down a ramp. Wheel accelerates very slowly while on ramp but accelerates away when it reaches the floor. B. Roll objects down a hill (disc, hoop, sphere ). C. Bird with lead weights in wings so that it balances on its nose. D. Set of 9 planks hanging over the edge of a table.
11/6 F	A. Yo-yo on string. B. Bowling ball sliding then rolling. This is really dynamics, not energy. C. Bike chain. Spin this and see it slide across the floor. I need to see this. D. Could we have something like a billiard table?
11/9 M	A. Giant wooden yo-yo. Vary the angle at which one pulls and yo-yo either rolls string onto it or off of it. B. Broomstick and wine glasses. C. A hinged stick has a small ball resting in a cup at the free end. When the stick falls the acceleration of the free and is greater than g and the ball is released from the cup. It is then caught on another cup. D Could we have ladder with casters on both ends?
11/11 W	A. Bicycle wheel and stool demo B. Disk with weights attached. Demonstrate balanced and unbalanced motion.
11/13 F	2^nd exam
11/16 M	A. Gyroscopes. B. Tops. C. Bike wheel with an axle which can be supported at one end. Wheel is spun and the axis processes.
11/18 W
11/20 F
11/23 M
11/25 W
11/27 F
11/30 M	A. Examples of oscillators: pendulum, mass plus spring, torsional oscillator. One can vary the position of the weights on the torsional oscillator.
12/2 W	SHM oscillators: simple pendulum, torsional pendulum, vertical mass plus springs
12/4 F
12/7 M	Damped oscillations on an oscilloscope with tuning forks.
12/9 W	A. Breaking glass with sound. B. Could we have a resonance of Jello? C. Resonance demonstration with mechanical driver of spring and mass. D. Water balloon resonance.