Motion in Two Dimensions
PIRA classification 1D
1D10. Displacement in Two Dimensions
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 motionĀ |
A Turn table with a ball that rotates with an arrow on top is projected on a screen by a arc lamp. |
1D10.60 |
measuring angular velocity |
Use an electronic strobe to measure the angular velocity of a fan blade or other rotating objects. |
1D15. Velocity, Position, and Acceleration
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. |
1D40. Motion of the Center of Mass
PIRA # |
Demonstration Name |
Abstract |
1D40.10 |
throw objects |
A slab of Styrofoam with lights 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. |
1D40.13 |
throw objects |
A bunch of junk is tied together with strings and thrown across the room. |
1D40.15 |
loaded bolas |
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 system |
Two unequal masses are fastened to the ends of a rigid bar. Spin the system about holes drilled in the bar at and off the center of mass. |
1D40.50 |
air track 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. |
1D40.50 |
air track pendulum glider |
A large glider with a pendulum on top of it. |
1D40.50 |
air track pendulum glider |
A double pendulum with equal masses are hung below a glider. A pendulums can swing together or not. |
1D40.51 |
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. |
1D40.60 |
satellite oscillation |
Discussion of the LDEF satellite (30'x14'dia.) as an example where the distinction between the center of mass and center of gravity is important. |
1D50. Central Forces
PIRA # |
Demonstration Name |
Abstract |
1D50.10 |
ball on a string |
Tie a lightweight ball to a sting and twirl around in a vertical circle. |
1D50.10 |
ball on a string |
Tie a whiffle ball to a sting and 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 |
whirligig |
A large ball and a small ball fastened to opposite ends of a string which is threaded through a handle. |
1D50.20 |
centripetal force apparatus |
Use a glass tube for the holder and rubber stoppers for the masses. |
1D50.20 |
whirligig |
A large and small ball are on opposite sides of a string threaded through a handle. |
1D50.20 |
whirligig |
Two balls - 1 kg, 100 g - are attached to the ends of a 1 m string passing through a small hollow tube. Twirl a ball around your head. |
1D50.20 |
ball on cord |
A string with a rubber ball on one end passes through a plastic sleeve and weights are attached to a loop at the other end. |
1D50.23 |
whirlygig |
Apparatus Drawings Project No. 25: Construction of a low friction conical pendulum. |
1D50.23 |
whirligig |
The front axle of a bike is used for a whirligig support. |
1D50.25 |
conical pendulum |
A ceiling mounted bowling ball pendulum is used as a conical pendulum. |
1D50.25 |
conical pendulum |
A ball on a cord is rotated mechanically at a steady slow speed. |
1D50.26 |
plane on string |
A model plane flies around on a string defining a conical pendulum. |
1D50.27 |
conical pendulum |
Motorized triple bifilar coaxial conical pendula are used to demonstrate critical period. |
1D50.28 |
conical pendulum |
The main bearing of a conical pendulum is from a bicycle wheel axle. See also under whrilygig (AJP 30,221) |
1D50.28 |
conical pendulum |
The front wheel axle of a bike is used as a good bearing for a conical pendulum where the string tension is set by a counterweight. See AJP 31(1),58. |
1D50.29 |
conical pendulum game |
Swing a conical pendulum so it will strike a peg directly under the support on some swing other than the first. |
1D50.30 |
canival ride model |
A toy person is held on a vertical card at the edge of a turntable when the turntable is spun fast enough. |
1D50.30 |
roundup |
A toy person stands on the inside wall of a rotating cylinder. |
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 |
Swing a bucket of water in a verticle circle over your head. |
1D50.40 |
pail of water, pail of nails |
Swing a bucket of water in a vertical circle over your head. If nails are used, they can be heard dropping away from the bottom of the can. |
1D50.40 |
pail of water |
A pail of water is whirled around in a vertical circle. |
1D50.40 |
pail of water |
Swing a bucket of water over your head. |
1D50.40 |
whirling bucket of water |
Rotate a bucket of water in a vertical circle. |
1D50.45 |
penny on the coathanger |
Place a penny on an elongated coat hanger and rotate around your finger. |
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. |
1D50.45 |
penny on the coathanger |
The wire coat hanger is whirled about the vertical plane by the hook without dislodging the dime on the middle of the lower bar. |
1D50.45 |
penny on the coathanger |
Place a coin on the coat hanger and rotate it about the finger. |
1D50.45 |
coin on coat hanger |
A coin is placed on the flat of the hook of an elongated coat hanger and twirled around. |
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. |
1D50.50 |
Welch centripetal force review |
Uses no motor, self contained static force measurement. |
1D50.50 |
Welch centripetal force |
The angular velocity and mass needed to stretch a spring a certain distance are compared. |
1D50.51 |
Welch centripetal force modification |
Two modifications to the apparatus. |
1D50.51 |
Welch centripetal force |
A modification to improve the Sargent-Welch 9030 centripetal force apparatus. |
1D50.51 |
Welch centripetal force modification |
Improvements to the Welch centripetal force apparatus. |
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. |
1D50.53 |
Cenco centripetal force |
A relay starts the counter and clock so three hands are not needed when using the Cenco 74470 apparatus. |
1D50.53 |
Cenco centripetal force |
Lab apparatus used as a demonstration. |
1D50.54 |
Cenco centripetal force modification |
Replace the screw adjustment for the fixed end of the spring with a movable plate. |
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. |
1D50.62 |
ball in a megaphone |
Throw a ball into a megaphone and it turns around and comes out the wide end. |
1D50.65 |
banked track |
A turntable can be rotated at various angular frequencies. Objects can be placed at different radii. A small platform 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 |
puzzle |
Two balls in a box must be caught in end pockets simultaneously. |
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. |
1D50.70 |
rolling chain |
A flexible chain is spun on a motorized pulley. When it is released, it maintains rigidity as it rolls down the lecture bench. |
1D50.70 |
rolling chain |
A loop of chain is brought up to speed on a motorized disc and when released rolls down the lecture bench over obstacles. |
1D50.70 |
rolling chain |
A loop of chain spun on a wheel and forced off remains rigid for some time. |
1D50.70 |
spinning chain |
Spin a flexible chain rapidly enough that it acts as a solid object. |
1D52. Deformation by Central Forces
1D55. Centrifugal Escape
1D60. Projectile Motion
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