Physics 314 (Survey of Astronomy) Exam 2 Please show all significant steps clearly in all problems. Summary: Physics 314 (Survey of Astronomy) Exam 2 Please show all significant steps clearly in all problems. Please give clear, legible, and reasonably complete (although brief) responses to qualitative questions. See the last page for values of constants. 1. Black holes (a) (4) Calculate the escape velocity from the surface of the Earth, which has a radius of 6.37!106 meters and a mass of 5.98!1024 kg. (The sum of the kinetic energy and gravitational potential energy is the same at the Earth's surface as at infinity, so you can first algebraically solve for the escape velocity in terms of the known quantities.) (b) (4) Again using nonrelativistic physics and Newtonian gravity, just as in part (a), calculate the Schwarzschild radius of a black hole with mass M . Comment on the validity of each of these two approximations for very strong gravitational fields, and on the validity of the final answer. (c) (4) Calculate the numerical value of the Schwarzschild radius for a supermassive black hole with a mass of 3!106 M! . Give your answer in light hours. (1 hour = 3600 sec.) (d) (4) Is there evidence for a supermassive black hole like that in part (c)? Where is it, and what is the evidence? (e) (4) What are the identifying observable characteristics of a stellar-sized black hole in a binary system? Collections: Physics