The force of gravity exists between . . . . . . . . objects, but cannot be felt until the mass of objects, such as planets, is very high-

A. Gravitational force B. Centrifugal force C. Concentric force D. Nuclear force

A. Satellite is kept in orbit by remote control from ground station B. Satellite is kept in orbit by retro-rocket and solar energy keeps it moving around the earth C. Satellite requires energy from solar panels and solid fuels for orbiting D. Satellite does not required any energy for orbiting

A. The object will go into space B. It will return to Earth C. It will rotate into the orbit of Earth D. It will burst out

A. more B. less C. zero D. depends on G force