View Single Post
Doc Al
#4
Feb22-12, 11:38 AM
Mentor
Doc Al's Avatar
P: 41,306
What is centripetal force

Quote Quote by kushan View Post
then how does this centripetal force comes in , there are 4 fundamental forces and all other forces can be taken from these forces , but centripetal force ?
which fundamental force makes centripetal force ?
Centripetal force is just the name we give to a force acting towards the center of some circular motion. The particular forces that give rise to the centripetal force depend on the particular circumstances. In the case of a satellite in orbit around a planet, gravity provides the centripetal force.
and why is that when a satellite revolving around a planet , acted by gravity, force is equated to mv^2/r , but that is analogous to F=ma , so there is only one force acting that is gravity so satellite should fall but it doesnt ...
Since the satellite is centripetally accelerating, there must be a net centripetal force (provided by gravity). Since that force remains perpendicular to the motion, the satellite continually changes direction. Note that forces cause changes in velocity. Since the force acts towards the planet, the change in the satellite's velocity is towards the planet. (If the satellite were not moving, then it would surely fall. But it is moving--at just the right speed to maintain a circular orbit.)