Free Fall: The phenomenon of falling object without any obstacle or resistance is called free fall. Inside earth’s gravitational field absolute free fall is not possible as there is air resistance. Free fall can be felt in other planet’s gravitational field where there is very thin air or no air.
Examples of objects in free fall include: A spacecraft (in space) with propulsion off
(e.g. in a continuous orbit, or on a suborbital trajectory (ballistics) going
up for some minutes, and then down). An object dropped at the top of a drop tube.
Question 1. Is fall of parachute on earth’s atmosphere a free fall? Why?
Ans: No, its not a free fall because there is thick layer of air in earth’s atmosphere which creates friction with parachute and the velocity of parachute decreases.
Weightlessness: The condition at which value of acceleration due to gravity(g) as well as weight of an object is felt zero is called weightlessness.
Earth-orbiting astronauts are weightless for the same reasons that riders of a free-falling amusement park ride or a free-falling elevator are weightless. They are weightless because there is no external contact force pushing or pulling upon their body. In each case, gravity is the only force acting upon their body.
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