Recent content by fifel85

Homework Statement Calculate the mass and radius of a black hole with density 750 kg/m^3. Homework Equations The Attempt at a Solution In a previous question, I already used the Schwarzschild radius to come up with a formula for the density of a black hole: D = (mass/(4/3pi((2Gmass/c^2)^3). I...

Oh, ok, thanks! 300m/1 microsecond is the speed of light (c), so I can just separate that out...so v = c (sqrt(1-v^2/c^2). Solving for v, I get 2.12*10^8 m/s relative velocity, or about 70% the speed of light. ? Thanks so much!

Homework Statement Two spaceships, each measuring 300 m in its own rest frame, pass by each other traveling in opposite directions. Instruments on board spaceship A determine that the front of spaceship A requires 1 microsecond to traverse the full length of B. What is the relative velocity...