Hi, The force of gravity is the centripetal force when an object is in motion. But in projectile motion, where the speed is not enough to keep it in orbit, could the force of gravity be equated to centripetal force? I'm trying to understand if all types of curved motion can be explained by centripetal force, or put differently, instances where the concept of centripetal force applies. For example, if a projectile is allowed to fall right through earth matter (instead of colliding with the ground (in our imagination, of course)), would it be able to orbit it in some kind of weird curve? Would the centripetal force apply here? If it can, then it must have to be different than the force of gravity, which is strange because centripetal force is always just a manifestation of some other force and the only force involved in projectile/satellite motion is gravity.. I hope you guys are getting my point..