[:PiraScheme#Mechanics: Table of Mechanics]

[:Measurement: Mechanics (1A): Measurement]

[:MotionIn2D: Mechanics (1D): Motion in Two Dimensions]

[:Demonstrations:Lecture Demonstrations]

Motion in One Dimension

PIRA classification 1C

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

1C10. Velocity


Demonstration Name



Bulldozer or Cart on Moving Sheet

The bulldozer or cart moves in the same or opposite direction as the sheet which moves beneath it, to show addition and subtraction of velocities.


PASCO Dynamic Cart

Show the PASCO cart moving on the PASCO track.


Block of Wood on a String

With a stopwatch, measure the time it takes to pull it  across the table at constant velocity in front of a meter stick.


Constant Velocity (Air Track & Glider)

Dots are superimposed on the screen every half second to mark the position of the air glider.


Velocity Air Track and Glider

Use a level air track, the PASCO echo system and a computer to show several velocities. 


Approaching Instantaneous Velocity

An air cart is given a reproducible velocity by a solenoid kicker. Flags of decreasing length interrupt a photo timer.


Strobed Disc

Look at a fluorescent spot on a 1725rpm disc with a stroboscope at multiples of the frequency to demonstrate the limiting process.


Terminal Velocity

A marble is dropped in to a cylinder of glycerine and quickly reaches terminal velocity. The marble obtains a slow and constant velocity that can be measured.

1C20. Uniform Acceleration


Demonstration Name



Penny and Cotton (guinea and feather)

Invert a large glass tube that contains a penny and a small cotton ball within; Invert first with air and again when evacuated.


Drop Wooden and Lead Balls

Show that the two balls, one substantially heavier than the other, when dropped simultaneously have the same acceleration and hit the ground at the same time. The two balls are the same size.


Equal Time & Equal Distance

Two separate ropes strung through tennis balls are hung from the ceiling. On the first rope the tennis balls are spaced equidistantly (ex. every 3 feet). On the second rope the balls are spaced in a manner which represents the position of a falling ball at equal time intervals. (ex. every half second i.e. one ball at the top, one ball 4 ft below it, another 16 ft from the top, another 36 ft from the top, etc.)


Inclined Air Track

Using the PASCO interface, the echo censor and a computer to show the acceleration, velocity, or displacement graphs vs. time. The data is obtained from a cart on an inclined air track as it accelerates down and rebounds. (PASCO mass cars and track can also be used here.)


Acceleration "Al" Track I

A large steel ball accelerates down the inclined track as a metronome ticks at constant time intervals.


Acceleration "Al" track II

A large steel ball accelerates down the inclined track and onto a flat track as a metronome ticks at constant time intervals.


Duff's Plane

A ball leaves a trail as it oscillates back and forth while rolling down a chalk covered trough.

1C30. Measuring g


Demonstration Name



Free Fall Timer

Drop a ball and time the fall.


Dropping Balls

A ball is released by an electromagnet and a clock started. The catcher stops the clock, thus measuring the duration of the fall.


Free Fall Spark Apparatus

A bob falls along a length spark tape to show the position of the bob at constant time intervals.


"Videostrobe" with Falling Drops

Use the 60 Hz refresh rate of a video monitor to strobe falling drops by adjusting the rate to 60 Hz and having the stream fall past the screen.


Catch a Meter Stick, Reaction time

Drop a meter stick and have a student catch it. Distance can be converted to reaction time.


Catch a Dollar, Reaction time

Have a student try to catch a dollar starting with the fingers at the midpoint.


Pendulum Timed Free Fall

A pendulum released from the side hits a ball dropped from the specific height that gives a fall time equal to a quarter period of the pendulum.


Many Bounce Method

Time a bouncing ball for many bounces and determine g using the coefficient of restitution.