Correct Option: E

The reason astronauts experience weightlessness which orbiting the earth in spaceships is that they are in free fall. A spacecraft in orbit is falling towards the Earth, because of gravity, but it is moving forward in its orbit fast enough that the path it follows is a curve that is a closed ellipse. Hence, the astronaut is not able to exert his mass on its surface. This condition is called weightlessness condition.If the spacecraft does not move quickly enough, it would fall prey to the effects of earth’s gravitational field and fall to the earth. Contrary to common misconception, there is no such thing as ‘Zero Gravity.’ Gravity is everywhere in the universe and manifests itself in black holes, celestial orbits, ocean tides, and even our own weight. The International Space Station, the space shuttle, and satellites are designed to stay in orbit, neither falling to the ground nor shooting off into space. Best option : (4) Orbital Motion