1. The moon's mass is only about 1.2% of Earth's mass (0.012 E), while the Earth's mass is 1 E. Given that the moon is about 300,000 km from the Earth, what is the force of gravity that the moon will feel from the Earth?

2. Now let's say that the moon's mass doubled for some reason. How would this affect the same force of gravity that the moon feels from the Earth?

3. Now let's say that the moon didn't double in mass, but got closer to the Earth. Instead of being 300,000 km from the Earth, what if the moon is only 150,000 km from the Earth. How does this affect the force of gravity that the moon will feel from the Earth?

4. Say as a scientist you found 2 new planets in our solar system, just orbiting around our Sun (mass = 333,000 E). Planet X is 3 times larger than Earth (3 E) and is about 2 AU from the Sun. On the other hand, Planet Y is only 1.5 times larger than Earth (1.5 E) and is about 1.5 AU from the Sun. Which planet do you think feels the most force of gravity from the Sun, according to the equation?