The figure shows two observers 20 m apart on a line that connects them and a spherical light source. If the observer nearer the source measures a light intensity 46 % greater than the other observer, how far is the nearer observer from the source?

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?