Previous Year Question
If an apple is released from an orbiting spaceship, it will
fall towards the Earth
move at a lower speed
move along with the spaceship at the same speed
move at a higher speed
Correct Answer: C
Detailed Solution
The orbiting spacecraft and the apple inside it are already moving around the Earth with approximately the same orbital velocity.
When the apple is simply released, no additional forward or backward velocity is imparted to it relative to the spacecraft.
Therefore, at the instant of release, its tangential velocity remains the same as that of the spacecraft.
An important point is that gravity does not disappear in orbit. Earth's gravitational force continues to accelerate both the spacecraft and the apple towards the Earth. However, their tangential velocity is sufficiently high that instead of hitting the surface, they remain in continuous free fall around the Earth. NASA explains orbital motion in the same way—as continuous free fall around the Earth.
Therefore, to an observer inside the spacecraft, the apple appears to move with the spacecraft at approximately the same speed or to float relative to it.
Here, option (a), “fall towards the Earth,” is misleading if taken alone. The apple is gravitationally falling towards Earth, but so is the spacecraft; both continue orbiting the Earth together.