PIRA # |
Demonstration Name |
Demonstration Description |
Image Available |
| 1D15.50 | Brachistochrone | Each end of a track forms a brachistochrone. Balls released at any height on the brachistochrones reach the middle at the same time (details). |
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| 1D40.12 | Optical Hammer | Mark the center of gravity of a hammer with battery powered lights and throw in darkened room to show smooth path(details). | Yes |
| 1D60.30 | Shoot the Monkey | A gun shoots at a target, released when the gun is fired. The ball hits the target in midair(details). |
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| 1D60.65 | Water Parabola | Hook a nozzle to the house water through an additional regulator to reduce pressure fluctuations. Shoot at varying angles into a water trough. Project stream using overhead with grid(details). |
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| 1D50.70 | Rolling Chain | A loop of chain is spun up on a disc and released to roll down the lecture bench as a rigid hoop(details). | Yes |
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Rolling Bowling Ball | A bowling ball is rolled down an inclined track with clocks positioned at regular intervals and acceleration is observed (details). |
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equipment
- brachistochrone
- three balls
setup
- minimal
estimated time
- 5 minutes
additional instructions
- release balls from top of track and observe that they all reach the bottom at same time
equipment
- a hammer which has a battery powered LED attached at it's center of mass
setup
- minimal
estimated time
- 5 minutes
additional instructions
- The hammer is first thrown (carefully) across the front of the room. Then the classroom lights are turned off and the LED is turned on. The hammer is thrown again and the LED shows the smooth parabolic shape of the center of mass.
equipment
- monkey
- Pasco shooter and target apparatus
- box of sawdust as landing pad
setup
- 5-10 minutes
estimated time
- 5 minutes (reepeated trials)
additional instructions
- first plug in power supply and make sure control box is "disarmed"
- hang the target and then aim the shooter
- load the projectile and arm the control box
- pull firing cord (without jerking it)
equipment
- water hose
- overhead
- grid transparency
setup
- 5-10 minutes to set-up water hose to ensure it lands in the sink, as well as placing the overhead where the water stream will cross it's projection
estimated time
- 5-10 minutes by demonstrating various angles of water stream
additional instructions
- none
equipment
- drill
- loop of chain which is fit around a disk (disk should attach to the drill)
setup
- 5 minutes to practice
estimated time
- 5 minutes
additional instructions
- Attach the disk to the drill, with the loop of chain around the disk. Start the drill rotating with the disk perpindicular to the tabletop. Slowly inch the chain off of the disk. The chain will roll down the tabletop keeping it's rigid circular shape.
Please feel free to offer any hints or suggestions on these demonstrations to ed@physics.wm.eduequipment
- bowling ball
- inclined track (10-12 feet in length)
- 4-6 large timer clocks
setup
- 10-15 minutes as well as time to do a few practice runs
estimated time
- 5 minutes
additional instructions
Have a student posistioned at each clock to record the time it takes for the bowling ball to reach it. In addition, place a student at the end of the track for bowling ball recovery. Note the increase in speed as the bowling ball travels down the track, but that the acceleration is constant.
