CBSE Class 9 Answered
Weightlessness is a peculiar phenomena which refers to the absence of apparent weight of an object, so an object would possess no weight. This generally occurs in the absence of gravitational forces.
The weight of a body is felt due to the attractive force of earths gravity. If this force of attraction of the earth is somehow cancelled, or nor present then the body experiences no force towards the centre of the earth. This condition is called weightlessness.
Weightlessness is experienced by astronauts in the orbits around the earth because the gravitational force of attraction of the earth is cancelled by the force that appears because of the circular motion of the astronaut around the earth. Weightlessness is also observed during free fall that is if a lift allowed to fall; the people inside the lift will experience no weight.