What is the Radius of a Black Hole If Earth Were Compressed?

AI Thread Summary
A black hole's gravitational field is so intense that light cannot escape. For Earth to become a black hole, it must be compressed to a radius of approximately 1 cm, as calculated using the formula r_s = 2GM/c^2. This compression would significantly increase Earth's gravitational field, allowing it to reach the necessary escape velocity for light. However, this scenario is purely hypothetical and not physically feasible. Understanding these principles highlights the relationship between mass and the formation of black holes.
yxgao
Messages
122
Reaction score
0
Black Holes Gre.67
67. A black hole is an object whose gravitational field is so strong that even light cannot escape. To what approximate radius would Earth (mass = 5.98 x 10^24

kilograms) have to be compressed in order to become a black hole?
a. 1 nm
b. 1 microm
c. 1 cm
d. 100 m
e. 10 km

the answer is C.
 
Physics news on Phys.org
r_s = \frac{2 G M}{c^2}

- Warren
 
1 cm

The radius of a black hole is directly proportional to its mass. In order for Earth to become a black hole, it would need to be compressed to a radius of approximately 1 cm. This is because Earth's current mass is not enough to create a strong enough gravitational field to overcome the escape velocity of light. However, if the Earth were compressed to a radius of 1 cm, its mass would be significantly increased, resulting in a strong enough gravitational field to create a black hole. It is important to note that this is a hypothetical scenario, as it is not physically possible to compress Earth to such a small size.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top