An electrostatic paint sprayer has a 0.200-m-diameter metal sphere at a potential of 25.0 kV that repels paint droplets onto a grounded object. (a) What charge is on the sphere? (b) What charge must a 0.100-mg drop of paint have to arrive at the object with a speed of 10.0 m/s?

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?