Grav. Force - Mass of an object

  • Thread starter Thread starter ecthelion4
  • Start date Start date
  • Tags Tags
    Force Mass
Click For Summary
SUMMARY

The discussion revolves around calculating the mass of a black hole based on the orbital motion of a proton traveling at 0.999 times the speed of light, positioned 4362 km from the black hole's center. The gravitational force equation, F=(Gm1*m2)/d^2, is utilized alongside the concept of centripetal force, expressed as F=(m*v^2)/r. The speed of the proton is determined to be 299,792,458 m/s multiplied by 0.999, which is essential for calculating the gravitational force exerted by the black hole.

PREREQUISITES
  • Understanding of gravitational force equations, specifically F=(Gm1*m2)/d^2.
  • Knowledge of centripetal force and its application in circular motion, F=(m*v^2)/r.
  • Familiarity with the speed of light as a constant, specifically 299,792,458 m/s.
  • Basic understanding of relativistic physics, particularly the implications of velocities approaching the speed of light.
NEXT STEPS
  • Calculate the gravitational force exerted by a black hole using the mass of the proton and its orbital speed.
  • Explore the implications of relativistic speeds on mass and force calculations.
  • Investigate the relationship between distance from a black hole and gravitational force.
  • Learn about the Schwarzschild radius and its relevance to black hole mass calculations.
USEFUL FOR

Physics students, astrophysicists, and anyone interested in gravitational physics and black hole dynamics will benefit from this discussion.

ecthelion4
Messages
24
Reaction score
0

Homework Statement




A proton moving at 0.999 of the speed of light orbits a black hole 4362km from the center of the attractor. What is the mass of the black hole?

Homework Equations



F=(Gm1*m2)/d^2

The Attempt at a Solution



Assuming the above is correct, a proton I think has constant mass of 1.6726*[(10)^(-27)], I know the distance, and G is constant. Since what I need is mass of black hole I'm assuming there's a way to find the force using the proton's speed.
 
Physics news on Phys.org
The gravity of the black hole is acting as the central force. So what is the definition of a central force? Think Newton's second law for circular motion.
 
super, i figured put the problem, the force would be equal to (m*v^2)/r

now the only thing I am missing is v, which is .999 of the speed of light, but what does that mean?
 
Do you know what the speed of light is in a vacuum? It's a constant. The 0.999 is how much of the speed of light the proton is moving at.
 
ok, so if the speed of light is 299,792,458 m/s, then the proton's speed would be that times .999 right?
 
ecthelion4 said:
ok, so if the speed of light is 299,792,458 m/s, then the proton's speed would be that times .999 right?

That's right.
 

Similar threads

Replies
17
Views
2K
  • · Replies 2 ·
Replies
2
Views
846
  • · Replies 3 ·
Replies
3
Views
871
  • · Replies 21 ·
Replies
21
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
10
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K