Eureka! Season 2, Episode 5: The Pulley

1

The Inclined Plane

How can someone lift a very heavy load? If one could slice the load into pieces, that would trade increased distance for decreased effort. But since one can't break things because they are so heavy, the inclined plane comes into play.

5 min

2

The Lever

A teeter-totter is the perfect demonstration of the lever, particularly if you are trying to ride a teeter-totter with someone heavier than you. Such is the Principle of the Lever.

5 min

3

Mechanical Advantage and Friction

Two professors compete to see who can lift a book with a lesser amount of force. The professor who uses a lever is more efficient than the inclined plane, once we factor in a basic double-edged sword called friction.

5 min

4

The Screw and the Wheel

All machines in the world can be traced to just two: the inclined plane and the lever. Even the wheel is just a circular lever whose fulcrum has become an axle. The screw? It's just a spiraling inclined plane.

5 min

5

The Pulley

Jack and Jill went up the hill and found a problem: how can they pull a pail of water from the bottom of a well? In this expanded nursery story, we find there is more to a pulley–and its mechanical advantage–than meets the eye.

5 min

6

Molecules in Solids

The first of six shows on heat and temperature, introduces molecules. Even though a solid object looks motionless, its molecules move back and forth in a lattice-work dance.

5 min

7

Molecules in Liquids

This episode sacrifices a chocolate rabbit on a hot day to illustrate the movement of molecules in liquids.

5 min

8

Evaporation and Condensation

No end of problems await the man who keeps fish for pets. Evaporation forces one to refill the tank. And he who thinks he can outsmart water vapor by keeping his fish in a refrigerated water tank, falls prey to Nature's countermeasure: condensation.

5 min

9

Expansion and Contraction

This lecture-packed show compares a balloon to a bunch of angry wasps to explain why gases expand and contract. It goes further than that. The expansion process also affects matter when it changes from one state to another.

5 min

10

Measuring Temperature

Given three bathtubs of varying temperature, the star of the show ""blunts"" his feet so that they can't tell temperature. Sure they can't. The human body can only tell changes in temperature in comparison to what it had been used to. It's up to an independent device: a thermometer and the scale devised by Anders Celsius.

5 min

11

Temperature vs. Heat

What is better to warm up a kiddie pool: a teacup of boiling water (100° Celsius) or a bucket of water at 50° Celsius? The answer tells you the difference between temperature and heat.

5 min

12

Atoms

There's more to matter than the molecules we had spent discussing in the previous six shows. This fourth unit produces that first look at atoms.

5 min

13

Electrons

An atom is made of mostly empty space. The electrons in an atom zoom around at fantastic speeds to create existence out of something that is mostly nothingness (at the atomic level).

5 min

14

Conduction

All objects conduct heat, of course, but get a look at objects from the atomic level and you'll see why some objects conduct heat faster than others.

5 min

15

Volume and Density

To set up audiences for The Convection of Heat, this question is posed: how can you fit eight junky cars into a small space?

5 min

16

Buoyancy

How come an anchor is easier to lift if it's in the water than in open air? It lies in the density of an object versus a certain quantity of water.

5 min

17

Convection

Now that the Principle of Buoyancy is understood, one can fully grasp The Convection of Heat. This is demonstrated with a furnace not being in the attic of a house.

5 min

18

Heat as Energy

An animated Count Rumford demonstrates, for the first time, how heat can be used to produce energy. The show converts a Calorie as the amount produced from 4200 joules of work.

5 min

19

Radiation Waves

Why does somebody stand in the shade on a hot day? This show introduces the third method by which heat can be transferred: radiation.

5 min

20

The Radiation Spectrum

Is it just your imagination that you are warmer when you wear dark clothes over white clothes? That actually sets off a reveliation on what color really is.

5 min