Why does the force of gravity change the speed of a satellite in an elliptical orbit?

1)The force of gravity is always tangent to the satellite motion.
2)Gravity speeds up the satellite as it moves away and slows it on its return.
3)The force of gravity is always perpendicular to the satellite motion.
4)Gravity slows the satellite as it moves away and speeds it up on its return.

1 answer

only the last is true.