Chapter 33, Problem 19TE

To determine

The reason for the intense gravitation near a black hole.

Answer to Problem 19TE

The intense gravitation near a black hole is due to high density of the hole.

Explanation of Solution

The mass of a black hole is almost the same as the star which collapsed to form a black hole. The star continues to collapse until the star attains maximum density. Thus, even though the black hole is small, it is highly dense.

When a person is beyond the star’s radius, the star’s mass is distributed, and the mass does not lie between the line connecting the person and the star. As a result, the gravitational force will be less.

Since the mass is concentrated in a very small area in a black hole, when someone goes near the hole, the entire mass lies between the person and the hole. Thus, the person experiences a high-intensity gravitational force near the black hole.

Conclusion:

Therefore, the intense gravitation near a black hole is due to high density of the hole.