Question

A student argues that as a satellite orbits the earth in a circular path, it moves with a constant velocity and therefore has no acceleration. The professor claims that the student is wrong since the satellite must have a centripetal acceleration as it moves in its circular orbit. What is wrong with the student's argument?

Answer 1

constant velocity means constant speed, constant direction. It would fly off in space. It must have a force applied moving it toward the Earth. If it has a Force, it must be accelerating.

Answer 2

Another way to say this is to look at it from an x and y perspective. If you are moving with no acceleration, then there would be no curve to the line. If a satelite is going forward(y), there is no (x) directional changes and thus no acceleration. If it moves around the circle, there is an added (x) direction when means it accelerates in that direction since it started at 0 and is moving to a new velocity in that (x) direction