Which of the following statements is/are incorrect?
1. The value of G on the Moon is equal to the value of G on Earth.
2. The gravitational force applied between two objects placed at a distance of 1 meter from each other, whose masses are of 2 kg each, is 26.68 × 10^-11 N.
3. Newton's law of gravity is valid only in the laboratory.
4. Force is inversely proportional to the square of the distance between two objects.

The movement of the Moon around the Earth is due to . . . . . . . .

A. Gravitational force

B. Centrifugal force

C. Concentric force

D. Nuclear force

Which one of the following statements about a satellite orbiting around the earth is correct?

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

What will happen if an object is thrown into space with the speed of 8 km/s?

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

Astronauts feel . . . . . . . . weight inside the spacecraft.

A. more

B. less

C. zero

D. depends on G force