A satellite is orbiting Earth in an approximately circular path. It completes one revolution each day (86,400 seconds). Its orbital distance is 22,500 kilometers from the Earth's center. What is the satellite's average speed?

- - The circumference of its orbit is

(pi) x (diameter)

= (pi) x (2 x radius)

= (pi) x (45,000 km) = 141,371.7 kilometers.

Average speed = (distance) / (time to cover the distance)

= (141,371.7 km) / (86,400 seconds)

= 1.636 kilometer per second.