Question

According to the law of universal gravitation, what would happen to the Earth if the Sun were replaced by a black hole?

1) The Earth would be pulled towards the black hole and eventually fall into it.
2) The Earth's orbit would remain unaffected.
3) The Earth would be pushed away from the black hole and move into a different orbit.
4) The Earth would be destroyed.

Answer 1

If the Sun were replaced by a black hole with the same mass, the Earth's orbit would remain the same, as the gravitational pull would be unchanged at Earth's distance from the black hole.

Step-by-step explanation:

According to the law of universal gravitation, if the Sun were replaced by a black hole of the same mass, the Earth's orbit would remain unaffected. This is because the gravitational force a significant distance away from the event horizon of a black hole is the same as that of any other object with the same mass.

Therefore, the Earth would continue orbiting the black hole as it did the Sun, since the mass (and thus the gravitational pull) would be unchanged.

It's only when an object gets very close to the event horizon of a black hole that the gravitational effects and the intense tidal forces would become deadly.

At a safe distance, such as Earth's current orbit, the black hole would pose no more gravitational threat to Earth than our current Sun does.