Question

Weightlessness produced in a spaceship is due to.

• A. Absence of inertia
• B. Absence of gravity due to earth
• C. Absence of accelerating force
• D. Free fall of the spaceship

Answer 1

The correct option is D Free fall of the spaceship

Weightlessness is the absence of any observable effects of gravitation. Examples of such situations are:

$\left(1\right)$ free fall of a spaceship(spaceship orbiting the Earth or more etc)

$\left(2\right)$ spacecraft drifting in Outerspace with its engines off

$\left(3\right)$ elevator falling freely in a vacuum (absence of any impediments to motion such as friction etc)

In the $1$st example, as the spaceship orbits the planet or a celestial object, the former appears to be in free falls towards the planet or celestial object as the centripetal force(gravitational force of attraction between spaceship and planet) and centrifugal force(as it orbits the planet) are balanced. Thus, both the forces are cancelled and the spaceship experiences weightlessness.

In the question given, other options such as

(B) "absence of gravity due to earth" isn't true, its just that force of gravity is counterbalanced by centrifugal force.

(C) "absence of accelerating force" isn't true either.

(A) All objects in motion(spaceship) have inertia- so A isn't right either.