In: Physics
Problem 1. A particle is orbiting a star of mass M in a circular orbit. (a, 2 POINTS) Find the equation that provides the orbital speed at a given distance r from the center of the star. (b, 1 POINT) From the result at (a), calculate at what distance rS the particle should be from the center of the star for its orbital speed to be equal to the speed of light, c (in this case, the particle would be a photon). (c, 1 POINT) Calculate that distance, rS for a star of mass equal to M = 10M, where the mass of the Sun is M = 1.99 × 1030 kg and c = 2.997925 × 105 km/s. (d, 4 POINTS) If the particle is a star orbiting the Galaxy, find and plot the function that describes the speed of the star as a function of its distance from the center of the Galaxy, r. You must calculate this in two cases, if the star is inside or outside the Galaxy. Assume the Galaxy is a homogeneous sphere of maximum radius RGalaxy and density ρ0. (e, 2 POINTS) If the Sun is inside the Galaxy, its orbital speed is 220 km/s and its distance from the center is 25 × 1019 m, what is the mass in kilograms of the part of the Galaxy contained within the orbit of the Sun?