1. Rotation is the spinning of a body on its axis. Revolution is the motion of a body as it orbits another body.
2. The equinox is the point at which the sun is directly above the equator. The
solstice is the point at which the sun is as far north or south of the equator as possible.
3. Spring tides occur when the sun, the Earth, and the moon are aligned. Neap tides occur when the positions of the sun, the Earth, and the moon form a 90° angle.
4. tides
5. eclipse
6. orbit
7. tidal range
8. D
9. D
10. D
11. C
12. Sample answer: Because sunlight hits the Earth’s surface differently depending on latitude, different areas experience different amounts of seasonal change.
13. Sample answer: The changes of seasons and length of day are caused by the Earth’s tilt, the Earth’s rotation on its axis, and the revolution of the Earth around the sun.
14. Sample answer: The phases of the moon are caused by the Earth’s movement and the moon’s orbit around the Earth.
15. Sample answer: A solar eclipse happens when the moon comes between the Earth and the sun and the shadow of the moon falls on part of the Earth. A lunar eclipse happens when the Earth comes between the sun and the moon and the shadow of the Earth falls on the moon.
16. Sample answer: High tides happen on the side of the Earth that is opposite the moon because of the gravitational pull of the Earth and the moon on each other as they revolve around each other.
17. Sample answer: The period of a planet’s revolution is determined by the planet’s semimajor axis.
18. Sample answer: The sun and the moon appear to move across the sky because of the Earth’s rotation on its axis.
19. Sample answer: A solar eclipse can happen during a new moon. The moon is between the Earth and the sun, and the disk of the moon covers or almost covers the disk of the sun.
20. Sample answer: The tidal range is small during neap tide because the sun, Earth, and moon form a right angle. The sun’s gravitational pull opposes the gravitational pull of the moon and reduces the bulge of water caused by the pull of the moon.
21.
22. Sample answer: Kepler could describe planetary orbits, but he could not explain why planets stay in their orbits. Newton’s law of gravitation explained why the planets orbit the sun.
23. Sample answer: Kepler’s first law of motion states that a planet revolves around the sun in an elliptical orbit. Kepler’s second law of motion states that planets move faster when they are
closer to the sun and slower when they are farther from the sun. Kepler’s third law explains the relationship between the period of a planet’s revolution and its semimajor axis. Planets
that are farther from the sun have a longer period of revolution.
24. Sample answer: The best time to pick a place to build the house is during a spring tide because spring tides are the highest tides.
25. Kepler’s first law of motion
26. Sample answer: The equation supports the law by allowing us to determine distances between a planet and the sun as the planet orbits the sun.
27. major axis
