The size of the force varies inversely as the square of the distance between the two charges. Therefore, if the distance between the two charges is doubled, the attraction or repulsion becomes weaker, decreasing to one-fourth of the original value.
Sound waves.
Eathquake P-Waves
The answer is D. centripetal force
This definition of centripetal force is a force acting towards the center of an object moving in a circular motion. Acceleration is the rate of which velocity changes over a period of time. If you pick a point on say a rotating circle and find the tangential velocity at each point it goes through, the acceleration would be towards the middle.
