Which road is faster? A kinematics concept Puzzler.

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...

What it shows:

This demonstration allows you to compare chalk’s compressive strength with its tensile strength.

How it works:

We use railroad chalk, which although being softer and harder to work, is nice and big and easy to see. A sample is placed in each of the two types of testing assembly (details in Setting it Up), and loads carefully applied. Railroad chalk has a tensile strength of 195kNm^-2 ± 30kNm^-2 (a load of 2.5 to 3.5kg) and a compressive strength of 500kNm^-2 ± 65kNm^-2 ( a load of 7 to 9kg).

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What is shows:

A neutral system of charges is rearranged...charge measured on one part is equal and opposite to the charge on another part. In that respect, this demonstration is not much different from the " 3 Sig Figs" demo in which voltage measurements are used. Conservation of charge is typically introduced in the first few lectures of an E&M course, before the concepts of voltage and capacitance are discussed. If voltage is the quantity...

What it shows:

Like visible light, invisible infra-red radiation can be refracted by lenses to produce an image on a screen. Indeed, a slide projector designed for visible light is used as the imaging device; a heat- sensitive screen makes the invisible IR image visible.

How it works:

Our IR source is a 1000 watt "lantern slide" projector ¹ from which we have removed the special heat-absorbing glass in the condenser assembly. The slide to be imaged is some kind of lettering, like the name of the course (Science A-29...