Why do astronauts (and cans of soft drink) float around in the Shuttle instead of falling?
A) the Shuttle is so far from the Earth, gravity is negligible
B) the Shuttle's gravity balances the Earth's, so that the net gravity is zero
C) the Shuttle is falling around the Earth (and everything aboard is in free fall)
D) the Shuttle has an antigravity device on board, developed by NASA
E) the rules Newton developed for gravity only hold on Earth, not once you get into space

Question

Quizplus · Accepted Answer

The reason astronauts (and cans of soft drink) float around in the Shuttle is because the Shuttle is falling around the Earth, which causes everything on board to be in free fall. This creates the sensation of weightlessness, as there is no force preventing everything from the falling with the Shuttle. The gravitational pull of the Earth is still present, but is balanced by the Shuttle's velocity, which keeps it in a constant state of free fall.

Why Do Astronauts (And Cans of Soft Drink) Float Around