PIRA #

Demonstration Name

Abstract

1F10.10

inertia balance

A torsion pendulum has cups that can be loaded with various masses.

1F10.10

inertia balance

A light torsion pendulum can be loaded with various masses.

1F10.10

inertia balance

Torsion pendulum as an inertia balance.

1F10.11

inertia balance

A horizontal leaf spring as an inertial balance.

1F10.11

inertia balance

Place masses on a platform supported by horizontal leaf springs.

1F10.12

inertia oscillation

A puck between two springs rolling on Dy-lite beads is timed with several different masses.

1F10.13

inertial equal arm balance

Publication of an unfinished demonstration, but up front about it. Shows circuit diagram for a indicator for a horizontal Roberval type balance on an acceleration cart.

1F10.13

inertia balance

Measure the period of a commercially available (?) inertia balance by using a stroboscope.

1F10.20

inertia bongs

Hit hanging 2"x4"x10" blocks of wood and steel with a hammer.

1F10.20

inertia bongs

Two large cylinders are suspended, one wood (3Kg) and one iron (50Kg). Students compare displacements when struck by a hammer or just push the things around.

1F10.25

foam rocks

Hit a real rock (granite) then a foam rock (looks like granite) with a hammer. Throw a form rock at some students.

1F10.25

foam rock

Hit a real rock and then a foam rock with a heavy mallet.

1F10.30

judging inertial mass

A blindfolded volunteer compares a mass on a string with a mass on a roller cart.

PIRA #

Demonstration Name

Abstract

1F20.10

inertia balls

Break the string on the top or bottom of a suspended mass.

1F20.10

inertia balls

Two heavy iron balls are hung separately between lengths of string. Pull on one and jerk on the other.

1F20.10

inertia balls

Two steel balls are suspended by strings with identical strings tied from their bottoms. Give a quick jerk to one and pull the other slowly.

1F20.10

inertial balls Break the string on the top or bottom of a suspended mass.

1F20.10

inertia ball

A mass is suspended between two cords. Pull slowly or jerk on the lower cord.

1F20.11

bowling ball inertia balls

Replace the standard 6 cm balls with bowling balls for increased visibility.

1F20.12

inertia balls

One mass is hung from a string and another mass hung below it. Jerk the lower mass to break one of the strings.

1F20.13

inertia stick

A long stick is supported from rings of filter paper at each end. Break the filter paper with a pull or the stick with a jerk.

1F20.15

inertia block

A 50 lb mass is mounted on rollers. A thread will pull it but a rope can be broken with a jerk.

1F20.16

inertia block

Tie a loop of 7/16" braided cotton cord through a hole in a 2"x4"x10" steel block. Pull and jerk with a hammer.

1F20.16

inertia block

A length of rope is tied to a 10 lb. block. A pull with a hammer will move the block but a jerk will break the rope.

1F20.16

inertia block

A rope is attached between a heavy iron ball and a hammer head. A fast swing of the hammer takes up the slack and breaks the rope without moving the ball.

1F20.18

inertia balls - analysis

For the more advanced reader. The system may be treated as a forced harmonic oscillator and the classical results of the demonstration are verified analytically. Surprises emerge.

1F20.20

smash your hand

Place a lead block on your hand and hit it with a hammer.

1F20.20

smash your hand

Hit a 10 lb. brick with a hammer while it rests on your hand.

1F20.21

smash your hand, etc.

Hit a 10 lb block on the hand or a 50 lb brick on the stomach with a hammer. Pound nails into a 50-75 lb wood block placed on a student's head.

1F20.22

hit the nail on the head

Place a physics book, then a 6"x6" block of wood on a student's head and drive a nail into the block.

1F20.22

hit the nail on the "head"

Drive a nail into a large block of wood placed on a student's head.

1F20.25

smash the block

An analysis of smashing a block on a volunteer sandwiched between two nail beds. Safety issues are discussed.

1F20.25

smash the block

A bed of nails is placed on the chest before smashing the block with a sledge.

1F20.26

vibrograph

An optical lever arrangement for magnifying small displacements of a large mass when the table is hit with a hammer.

1F20.30

the tablecloth pull

Pictures and a few hints.

1F20.30

tablecloth pull

Pull the tablecloth out from under a place setting.

1F20.30

tablecloth pull

Pull a low friction tablecloth from under a place setting.

1F20.33

inertia cylinder

Stand a 3/4" x 6" aluminum cylinder on a sheet of paper. Jerk the paper out from under the cylinder.

1F20.33

inertia cylinder

Jerk a sheet of paper out from under a thin steel cylinder.

1F20.34

card/coin snap

Snap a card out from under a tall object, e.g., a shipping tag from under a balanced claw hammer.

1F20.34

card/coin snap

Several inertia tricks.

1F20.34

card/coin snap

Snap a piece of cardboard from under a steel ball.

1F20.35

eggs and pizza pan

Set a pizza pan on three 2l beakers full of water, stand paper cylinders with eggs at the tops above the beakers, knock out the pizza pan.

1F20.35

blocks and broomstick

Egg on a spool, on a pie tin, on a beaker of water. Flex broom and knock out pie tin.

1F20.35

eggs and pizza pan

Place a pizza pan on three beakers, place cardboard tubes on the pan directly above the beakers, and eggs on the tubes. Knock out the pizza pan.

1F20.40

stick on wine glasses

Stick needles in the ends of a 3/4" sq x 4' clear pine bar. Place the needles on wine glasses full of water and break the stick with an iron bar.

1F20.50

shifted air track inertia

Support an air track on wheels. Move the air track under an air glider.

1F20.50

shifted air track inertia

Move the air track under an air track glider.

1F20.60

loose hammer head

A hammer handle may be tightened by pounding on the far end of the handle.

1F20.61

inertia cart

A cart has a pivoting arm with different masses but the same volume at the ends. The greater mass lags behind as the cart is accelerated.

1F20.62

string of weights

A string of weights connected by springs shows uneven deformation when jerked.

1F20.64

inertia of liquids

There are two horizontal glass tubes, one with a cork cylinder and the other with a lead cylinder. Strike the stopper at one end of the glass tubes with a hammer and watch the direction of the cylinders.

PIRA #

Demonstration Name

Abstract

1F30.10

persistence of motion (air track)

A single cart on the air track.

1F30.10

persistence of motion (air track)

A single cart on the air track.

1F30.11

air table puck

Air table with a puck.

1F30.13

CO2 block

A large piece of dry ice on a flat formica top wetted with alcohol.

1F30.21

water hammer

Some water in an evacuated test tube clicks when the water hits the end of the tube.

1F30.21

water hammer

Shut off the sink faucet and a water hammer may be heard. A small tube evacuated with some water shows the effect nicely.

1F30.21

water hammer

A tube is evacuated except for some water. When the tube is stopped suddenly, the water strikes the end of the tube with a click.

1F30.21

water hammer

Evacuate a glass tube containing water.

1F30.30

car on cart on cart

A small car on a skateboard on a large roller cart hits a stop level with the roller cart and the skateboard and car continue to move at constant velocity.

1F30.30

cart on a cart

A smaller roller cart is placed on a larger one. when the larger is stopped, the smaller continues.

1F30.40

nail by hand

Follow the directions in TPT 18(1),50.

1F30.40

hand pile driver

Drive a nail into wood with your bare hands.

1F30.50

pencil and plywood

Place a pencil in a brass tube hooked to a fire extinguisher. Fire the pencil into a 1/2" plywood board.

1F30.50

pencil and plywood

Use a CO2 extinguisher to fire a pencil through a 1/2" plywood.