Newton's Apple

Apple electronically released from platform; fall time given by special circuit and digital display.

What it shows:

This is a free-fall-from-rest experiment in which an apple (or any other object of comparable size) is dropped from the lecture hall ceiling into a catching bucket on the floor. By measuring the (1) distance and (2) duration of the fall, an accurate (± 0.022%) determination of the acceleration due to gravity can be made:


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Bosun's Chair

Block and tackle, or a simple pulley, attached to hall ceiling for lecturer to hoist self.

bosuns chair

Three-Legged Table

Triangular table supported by platform scales.

What it shows:

This is a two-dimensional version of the Loaded Beam demonstration.

How it works:

An equilateral triangular-shaped table is supported at each corner by a platform scale (same type as in "Loaded Beam"). One of our large (14.5 kg = 32 lb) weights is placed on the table. The scale readings vary with the position of the weight. The procedure to be followed in this demonstration...

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Erector Spinae Muscle Forces

A realistic model of the forces in the erector spinae muscles that support the back when bent over.

What it Shows:

This is an analysis of the tensions in muscles and forces on joints as an application of torques in static equilibrium situations. The muscles involved in supporting the human torso in a stooped position are realistically modeled, and the extraordinary large forces calculated and demonstrated.

How it Works:

When bending over into a stooped position, the principal muscles which support the back are the erector...

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Shoot the Monkey

Monkey released from platform is shot by simultaneously fired cannon.

What it shows:

This is a demonstration of the independence of the horizontal and vertical components of velocity of a projectile. Often referred to as "the monkey and hunter," the problem is the following. A hunter (at ground level) aims a gun at a monkey hanging from a branch high in a tree. The monkey, being very intelligent, does not want to be shot. It knows that light travels faster than bullets and reasons that, if it lets go of the branch the instant it sees the flash of the gun,...

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High Road, Low Road

Which road is faster? A kinematics concept Puzzler.

high low road

What it shows:

Horizontal and vertical motions are independent of each other.

How it works:

Two balls, starting with the same initial horizontal velocity, take two different paths: the...

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Ball shot up from PASCO cart is caught by same; a puzzler to ponder if track is tilted and cart accelerates down (or decelerates up).


Uniform Acceleration

Glider acceleration by an inclined air track or by a falling weight/string attachment; large ballbearing rolling on PASCO track (with strings).

uniform acceleration

Time lapse image of a ping pong ball rolling down an inclined track. The bottom image has computer generated lines...

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Galileo's Chandelier

galileo's chandelierBowling ball pendulum with burning candles stuck in holes, used as prop only.

What It Shows

Rumor has it that one day at the cathedral, Galileo watched the swinging of a chandelier after it had been displaced and lit. By using his own pulse as...

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