The electric potential difference between a charged sphere and Earth is 76.0 V when the sphere has been charged to 3.8×10−4 C. What is the capacitance of the sphere-Earth system? Help pls

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?