Many people assume that air resistance acting on a moving object will always make the object slow down. It can actually be responsible for making the object speed up. Consider a 100 kg Earth satellite in a circular orbit at an altitude of 400 km. A small force of air resistance makes the satellite drop into a circular orbit with an altitude of 200 km.(a) Calculate the satellite's initial speed.
m/s

(b) Calculate its final speed in this process.
m/s

(c) Calculate the initial energy of the satellite-Earth system. (Round your answer to two decimal places.)
×109 J

(d) Calculate the final energy of the system. (Round your answer to two decimal places.)
×109 J

(e) Show that the system has lost mechanical energy. Find the amount of the loss due to friction. (Round your answer to one decimal place.)

(f) What force makes the satellite's speed increase? Hint: You will find a free-body diagram useful in explaining your answer.