1. Since the Moon is gravitationally attracted to Earth, why doesn’t it simply crash into Earth? 2. Newton knew that if a cannonball were fired from a tall mountain, gravity would change its speed all...

1. Since the Moon is gravitationally attracted to Earth, why doesn’t it simply crash into Earth?

2. Newton knew that if a cannonball were fired from a tall mountain, gravity would change its speed all along its trajectory. But if it were fired fast enough to attain circular orbit, gravity would not change its speed. Discuss.