Recent content by rrfergus

Energy should be conserved. Momentum also, but I think energy conservation would be more relevant to the problem. I just don't know how to express the kinetic or potential energies in this context, or to calculate the time.

Homework Statement An observer falls radially inward toward a black hole of mass M, which is equal to 3 solar masses, starting with zero kinetic energy at infinity. How much time is measured by this observer as he travels between radii r1 = 6GM/c2 and the event horizon? Homework Equations...

Great! I got the right answer! Thank you so much!

Homework Statement This question has two parts; the first part I understand but the second part I do not. Part 1: What is the rotational energy of a planet about its spin axis? Model the planet as a uniform sphere of radius 6420 km, and mass 5.59x10^24 kg. Assume it has a rotational period...