qqp question1: How would one calculate the force of gravity on the 1.4-kg mass if it were 1.9x10^7 m above the earth's surface (that is it were four earth radii from earth's center)? question2: Jupiter's mass is about 300 times than that of Earth, yet surface gravity on Jupiter is only  about 2.5 times that of Earth's. What's the best explanation?