A star has a mass of 2.18 x 1030 kg and is moving in a circular orbit about the center of its galaxy. The radius of the orbit is 2.7 x 104 light-years (1 light-year = 9.5 x 1015 m), and the angular speed of the star is 1.5 x 10-15 rad/s. (a) Determine the tangential speed of the star. (b) What is the magnitude of the net force that acts on the star to keep it moving around the center of the galaxy? (a) Number i Units (b) Number i Units In an electrically heated home, the temperature of the ground in contact with a concrete basement wall is 13.4 C. The temperature at the inside surface of the wall is 19.4C. The wall is 0.18 m thick and has an area of 6.1 m. Assume that one kilowatt hour of electrical energy costs $0.10. How many hours are required for one dollar's worth of energy to be conducted through the wall? Number Units