posted by steph .
You have probably seen films of astronauts floating weightless in orbiting satellites. People often get the idea that the astronauts are weightless because they are so far from the gravity of the earth. Let us see if that explanation is correct.
Typically, such satellites orbit around 400 above the surface of the earth. If an astronaut weighs 630 on the ground, what will he weigh if he is 400 above the surface?
In light of your answer to part A, are the astronauts weightless because gravity is so weak? Why are they weightless?