What is weightlessness? Explain with examples.

(N/A) Weightlessness is a state in which the apparent weight of a body becomes zero. This occurs when a body is in a state of free fall,meaning the only force acting on it is gravity,and there is no normal reaction force from any surface.
Examples:
$(i)$ Free-falling lift: When a lift falls freely under gravity,its acceleration $a = g$. The apparent weight $W$ of a person of mass $m$ inside the lift is given by $W = m(g - a)$. Substituting $a = g$,we get $W = m(g - g) = 0$. Thus,the person experiences weightlessness.
$(ii)$ Satellites: An orbiting satellite is in a state of continuous free fall towards the Earth. The centripetal acceleration required for its orbit is provided by gravity $(a_c = g')$. Since the satellite and everything inside it are accelerating at the same rate towards the center of the Earth,there is no normal force between the objects and the floor of the satellite,leading to a state of weightlessness.