Science Study Guide 4th Quarter, 7th Grade

1. It will take approximately how many days for the Moon to move in its orbit from one position to the next position? 4 days

2. Why do the phases of the moon occur? Because a person on earth sees the sun lighting different parts of the moon.

3. Why do humans always see the same side of the moon? The moon rotates and revolves at approximately the same rate.

The larger a planet is, the stronger its gravitational pull. 4. What is the relationship between the mass of the planets and the relative strength of their gravitational pull? The larger a planet is, the stronger its gravitational pull.

5. When the Moon completely blocks out the view of the Sun for an observer on Earth what is it called? Total solar eclipse

6. What two things affect the earth’s tides? Sun and moon

7. Which of the following is an accurate comparison of the orbits of moons, comets and asteroids? Moons orbit planets, but comets and asteroids are in orbit around the sun

8. What is the actual shape of the Earth’s path around the Sun? Nearly circular (slightly elliptical)

9. The weight of things on Earth is the direct result of what? The gravitational force acting on your mass.

10. What will happen to the gravitational force of two objects that have the same distance between as the masses of these two objects increases? It increases

It will decrease and the period of revolution will increase. 11. If the average distance between Earth and the Sun were doubled what will happen to the gravitational pull? It will decrease and the period of revolution will increase.

12. According to Kepler’s Law of Planetary Motion, the farther a planet is located from the Sun, the longer its period of revolution.

13. How does the period of revolution of Jupiter compare to the period of revolution of all other planets in our Solar System? Jupiter has a shorter period of revolution than Neptune, but a longer period of revolution than Mercury, Venus, Earth and Mars.

14. What is the order of our cosmic address? Earth, solar system, milky way, universe.

15. Why do the gas planets have more moons than the inner planets? They have a stronger gravitational pull and can hold more moons.

16. Why does it take some planets less time to complete one revolution? The closer they are to the sun, the shorter the time needed to complete a revolution.

Outer planets have greater diameter than the inner planets.