21st Century Astronomy Chapter 04 |21 Questions| With Correct Answers.

If the Moon were 2 times closer to Earth than it is now, the gravitational force between Earth and the Moon would beChoose one:A. 16 times stronger.B. 4 times stronger.C. 2 times stronger.D. 8 times stronger. {Ans: B. 4 times stronger.}The "second" high tide is caused byChoose one:A. stronger gravity pulling on Earth on the side opposite the Moon.B. the Sun canceling out some of the Moon's gravity, no matter which way it pulls.C. the Sun, which always pulls in the opposite direction from the Moon.D. weaker gravity pulling on Earth on the side opposite the Moon. {Ans: D. weaker gravity pulling on Earth on the side opposite the Moon.}If you went to Mars, your weight would beChoose one:A. the same as on Earth.B. lower because Mars has lower mass and a smaller radius that together produce a lower gravitational force.C. higher because you are closer to the center of the planet.D. lower because Mars has two small moons instead of one big moon, so there's less tidal force. {Ans: B. lower because Mars has lower mass and a smaller radius that together produce a lower gravitational force.}For a pair of objects, the center of mass is