[:PiraScheme#Mechanics: Table of Mechanics]

[:MotionIn1D: Mechanics (1C): Motion in One Dimension]

[:RelativeMotion: Mechanics (1E): Relative Motion]

[:Demonstrations:Lecture Demonstrations]

Grayed Demos are either not available or haven't been built yet

PIRA #

Demonstration Name

Abstract

1D10.20

Cycloid Generator

A large spool with a light bulb fastened to the circumference is rolled along the table. With and without the lights on.

1D10.30

Inversor

A mechanical device that transforms rotational motion into rectilinear motion.

1D10.40

Mounted Wheel

A bicycle wheel marked with a radial line turns about its axis.

1D10.55

Projected circular motion 

A Turn table with a ball that rotates with an arrow on top is projected on a screen by a arc lamp with a pendulum above.

1D10.60

measuring angular velocity of a fan

Use an electronic strobe to measure the angular velocity of a fan blade or other rotating objects.

PIRA #

Demonstration Name

Abstract

1D15.10

ultrasonic detector and students

Have a student walk toward and away from a sonic ranger while observing plots of position, velocity, and acceleration on a projection of the Mac.

1D15.15

kick a moving ball

Kick a moving soccer ball on the floor or hit a moving croquet ball on the lecture bench with a mallet.

1D15.20

high road low road

Two objects start at the same velocity, one moves straight to the finish, the other traverses a valley. The problem: which wins?

1D15.30

catching the train

A ball accelerating down an incline catches and passes a ball moving at constant velocity on a horizontal track.

1D15.35

passing the train

A ball accelerates down an incline with a stripped rope moving at constant velocity in the background. The moment the ball has the same velocity as the rope is strikingly obvious. Repeat with the rope at a different constant velocity.

1D15.40

Galileo's circle

Several rods are mounted as cords of a large circle with one end of each rod top center. Beads released simultaneously at the top all reach the ends the rods at the same time.

1D15.45

brachistochrone track

Three tracks - straight line, parabola, and cycloid are mounted together. Triggers at each end control a timer. Details.

PIRA #

Demonstration Name

Abstract

1D40.10

Styrofoam with Light

An odd shaped piece of Styrofoam with a light placed at the center of gravity is tossed in the air.

1D40.11

center of mass disc

Throw a disc with uniform distribution and then offset the center of mass.

1D40.12

Hammer Toss

Mark the center of gravity of a hammer with a white spot. Throw it in the air and attach it to a hand drill to show it rotating smoothly.

1D40.15

Loaded Balls

Three balls tied together and tossed in the air

1D40.20

spinning block

A large wood block has two holes with felt tipped pens, one on the center of mass. Place the block on a large sheet of paper and hit off center with a hammer.

1D40.22

air table center of mass

A weighted block glides across an air table.

1D40.25

photographing center of motion

Photographing the center of velocity of a variety of rigid bodies, using a high speed CCD camera.

1D40.30

throw the dumbbell

A dumbbell with unequal masses is thrown without rotation when the force is applied at the center of mass.

1D40.35

[:Earth-Moon: Earth-Moon System]

Two unequal masses are fastened to the ends of a rigid bar with two holes in the bar. One hole is at the rod's center. The other hole is at the center of mass of this two body system.

1D40.50

hanging pendulum glider

A double pendulum hangs from an air track cart with a mounted spot marking the center of mass. Set the system in oscillation and the spot will remain still or translate smoothly.

1D40.51

pendulum glider

A large glider with a pendulum on top of it.

1D40.52

momentum pendulum

A pendulum support is free to move on rollers as the pendulum swings back and forth.

1D40.55

air track inchworm

The center of mass of two carts coupled with leaf springs is marked with a light or flag. Show oscillation about the center of mass or constant velocity of c of m.

PIRA #

Demonstration Name

Abstract

1D50.10

ball on a string

A ball is tied to a sting and then twirl around in a vertical circle.

1D50.15

arrow on a disk

Mount an arrow tangentially on the edge of a rotating disk.

1D50.20

Centripetal Force Apparatus

A large ball and a small ball fastened to opposite ends of a string which is threaded through a handle or glass tube.

1D50.25

Conical Pendulum

A ceiling mounted bowling ball pendulum is used as a conical pendulum, (or a ball on a cord is rotated mechanically at a steady slow speed.-not made yet)

1D50.26

plane on string

A model plane flies around on a string defining a conical pendulum.

1D50.30

Carnival ride model

A toy person is held on a vertical card at the edge of a turntable when the turntable is spun fast enough.

1D50.37

swinging up a weight

An arrangement whereby a swinging 500 g weight picks up a 1000 g weight.

1D50.40

pail of water

A pail of water is whirled around in a vertical circle.

1D50.45

penny on the coathanger

A penny is balanced on the hook of a coat hanger. The coat hanger is twirled around your finger and the penny doesn't fly off.

1D50.48

balls on a propeller

Balls sit in cups mounted on a swinging arm at .5 and 1.0 m. Calculate the period necessary to keep the ball in the outer cup and swing it around in time to a metronome.

1D50.50

Welch centripetal force

The angular velocity and mass needed to stretch a spring a certain distance are compared.

1D50.53

variable centripetal force

A new design for the apparatus that allows any two of the three variables of mass, angular velocity, and distance to be kept constant.

1D50.55

hand rotator

Two 2000 g spring balances are mounted on a rotator. Equal masses are attached to each and readings are taken at some rotational velocity.

1D50.60

banked track

A steel ball rolled down an incline into a funnel reaches an equilibrium level where it revolves in a horizontal plane.

1D50.65

Rotating Plate

A turntable can be rotated at various angular frequencies. Objects can be placed at different radii. [A small platform (needs to be made) can be attached which will swing out to the correct slope for any angular velocity. A device for measuring force is also shown.]

1D50.69

Spinning Puzzle

Two balls in a box must be caught in end pockets simultaneously.

1D50.70

Rolling Chain

A flexible chain is spun on a motorized Disk. When pushed off the disk, it maintains it's rigidity as it rolls across the lecture bench. Add block in it's path to make the chain jump into the air.

PIRA #

Demonstration Name

Abstract

1D52.10

flattening Earth

Flexible hoops flatten when spun on a rotator.

1D52.17

Empty Jug by Swirling

A jug will empty faster when swirled. (an out door Demo - too messy it a classroom)

1D52.20

parabolid of liquid

A cylindrical container with some water is rotated at a constant speed.

1D52.21

rotation water troughs

Two water containers are mounted on a rotating table. A rectangular container mounted radially shows half a parabola, and another formed in an arc of constant radius stays level.

1D52.24

rotating manometer

Tubing constructed in an "E" shape on its back is partly filled with water and rotated.

1D52.26

project mercury parabola

Spin a dish of mercury and image a light bulb on the ceiling.

1D52.30

balls in water centrifuge

Spin a bent glass tube filled with water containing cork and aluminum balls.

1D52.31

balls in water centrifuge

A long thin tube containing a brass ball, ping pong ball, and water is rotated.

1D52.33

cork and ball rotating in water

One cork is tied to the bottom, one ball is tied to the top of two cylinders full of water at the ends of a rotating bar.

1D52.33

rotating corks in water

Corks tied to the bottom of two jars full of water are first translated on a cart and then put on a pivot and rotated about the center.

1D52.34

car picture

A picture taken from inside a car of a candle, CO2 balloon, H2 balloon as the car is driven in uniform circular motion.

1D52.35

mercury/water centrifuge

A spherical glass bowl is spun and mercury forms a equatorial band with water above and below.

1D52.37

centrifuge

A hand cranked test tube centrifuge.

1D52.40a

rotating candle

A lighted candle in a chimney lamp on a rotating table will point to the center.

1D52.40b

rotating candle

Lighted candles in chimneys are rotated about the center of mass.

1D52.50

paper saw

A 6" paper disc placed on a dremmel tool cuts another sheet of paper.

1D52.50

paper saw

Typewriter paper will cut through other paper, Bristol board will cut through wood when spun at high speeds.

1D52.60

rubber wheel

A sponge rubber wheel with one spoke cut is rotated at high speed and viewed under stroboscopic light.

1D52.61

rotating rubber wheel

A rubber wheel stretches to a larger radius when spun.

PIRA #

Demonstration Name

Abstract

1D55.10

broken ring

A ball is rolled around the inside of a large open metal hoop. Students predict where the ball will go when it reaches the opening.

1D55.11

the big omega

A large wood circle with a gap is used with a boccie ball.

1D55.15

cut the string

Cut the string while swinging a ball overhead.

1D55.20

grinding wheel

Watch the path of sparks flying off a grinding wheel.

1D55.23

spinning disc with water

Red drops fly off a spinning disc leaving traces tangent to the disc.

1D55.30

falling off the merry-go-round

A turntable is rotated until objects slide or tip over.

1D55.33

train wrecks

Pictures of train wrecks at curves and some calculations.

1D55.50

air pump

Three mutually perpendicular discs are rotated about the intersection of two and air is drawn in the poles and expelled at the equator.

PIRA #

Demonstration Name

Abstract

1D60.05

ball to throw

Provide a large nerf ball, tennis ball, soft ball, or whatever ball is requested.

1D60.11

Ballistic cart

Instructor sits on a wheeled cart with a catapult to project a ball upward.

1D60.15

howitzer and tunnel on incline

Perform the howitzer and tunnel on an incline with the car starting at rest.

1D60.15

howitzer and tunnel on incline

Some strobe pictures and drawings show the ball is always above the cart relative to the incline, but not always above the cart relative to the horizontal.

1D60.16

vertical gun on accelerated car

Two cases: vertical gun on a car on an incline, and on a car accelerated by a mass on a string.

1D60.20

simultaneous fall

Device to drop one billiard ball and shoot another out.

1D60.20

simultaneous fall

A spring loaded device drops one ball and projects the other horizontally.

1D60.21

simulteanous fall

Instructor rolls a super-ball off the hand while walking at a constant velocity.

1D60.22

simultaneous fall

Roll a steel ball down an incline where it hits another, momentum exchange knocks the one out, and the other drops through a slot.

1D60.30

monkey and hunter (pasco)

A target is released when the gun is fired. The ball hits the target in midair.

1D60.31

monkey and hunter on incline

A simple and effective version using rolling balls on an inclined table.

1D60.34

monkey and hunter

A magnetic switch and solenoid release.

1D60.34

monkey and hunter

Plotting projectile motion using the OH projector, strobe photography, and an optoelectronic circuit for triggering the monkey drop.

1D60.35

monkey and hunter

Viewed from the free monkey frame, the bullet moves uniformly. Placing the hunter below the monkey can mislead students.

1D60.40

range of a gun

Shoot at 45, then calculate 30 or 60 and place the target.

1D60.43

range of a gun

Use the tennis ball serving machine to find muzzle velocity, range, etc.

1D60.45

range of a gun

Using a toy dart gun and a ball bearing weighted dart, the author gives a concise description for obtaining muzzle velocity used to predict the range at various angles.

1D60.50

parabolic trajectory

Four launching ramps are mounted to a large magnetic surfaced coordinate system. Magnet based metal hoops can be repositioned easily so the ball passes through all the hoops. Looks very nice.

1D60.50

parabolic path through rings

A ball launched off a ramp will pass through a set of rings.

1D60.55

parabolic trajectory on incline

A tennis ball covered with chalk dust is rolled across a tilted blackboard.

1D60.55

parabolic trajectory on incline

Fire a ball up an incline and trace the trajectory as it rolls on carbon paper.

1D60.55

air table parabolas

Pucks are projected across a tilted air track.

1D60.56

parabolic trajectory

Inexpensive apparatus for plotting parabolic trajectory by repeatedly hitting a carbon paper.

1D60.58

parabolic trajectory

A strobe picture is taken of the projectile motion of a golf ball. A method of analysis suited for a HS class is presented.

1D60.60

parabolic trajectory

A pivoted bar with several pendula of length proportional to the square of the distance point from the pivot.

1D60.60

parabolic trajectory

Uses the balls hanging from a stick device at the blackboard.

1D60.60

parabolic trajectory

A pivoted bar has pendula of length proportional to the square of the distance from the pivot point.

1D60.60

parabolic trajectory

A stream of water matches the position of balls of lengths 1,4,9,16,... at all angles of elevation.

1D60.65

parabolic trajectory - water stream

Apparatus Drawings Project No.33: The adjustable water nozzle has an arm extending in the direction of the nozzle with hanging arrows at intervals along the arm. Adjust the water pressure so the stream matches the arrow heads.

1D60.65

water trough trajectory

Hook a nozzle to the house water through an additional regulator to reduce pressure fluctuations. Shoot at varying angles into a water trough.

1D60.70

dropping the bomb

A mechanism to drop a bomb in slow motion from a model airplane.

1D60.71

juggling

Juggling higher trajectories requires slower hand motion.