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Unit 1 Expeditions for Science 1

Exploring Antarctica 2

A Land of Ice 4

Why Go？ 5

Ice and Glaciers 6

Icebergs 8

The Arctic 10

Is There Life？ 11

The Changing Earth 12

Expeditions in Review 12

Unit 2 Time and the Stars 15

Rotation of the Earth 16

From West to East 19

Day and Night 21

Noon and Midnight 22

Time and Rotation 22

The Clock in the Sky 24

Revolution of the Earth 26

Time in Review 26

Unit 3 Exploring the Sky 29

Up and Away 30

Lift 30

Drag 34

Thrust 36

The Controliable Parts 38

Helicopters 38

The Jet Airplane 39

Flight in Review 40

Unit 4 Sound and How It Travels 43

Sound Vibrations 44

The Speed of Sound 46

Flying Faster Than Sound 46

Controlling Sound Waves 47

Your Hearing 51

Silent Sounds 53

Unit 5 Electricity and Magnetism 57

What Can Magnets Do ？ 58

Electromagnets 62

Electromagnets and Sound 66

How Do Motors Work ？ 68

Unit 6 Understanding Heat 75

Temperature 75

Thermometers 77

Molecules in Motion 80

Expansion and Contraction 81

Traveling Heat 83

Conduction 86

Convection 88

Radiation 92

Removing Heat 95

Glossary 99