# Help With Centripetal Acceleration *

nychic3000
******help With Centripetal Acceleration*******

would someone PLEASE BE KIND ENOUGH TO PROVIDE ME WITH AN EXPLANATION OF CENTRIPETAL ACCELERATION? KINDA LIKE A SUMMARY OF THE TOPIC. EXAMPLES AND FORMULAS WOULD BE VERYYYYYYYYYYYYYYYYYYYYY APPRECIATED THANK YOU. PLEASE REPLY SOONNNN

## Answers and Replies

Staff Emeritus
Science Advisor
Gold Member
It all starts with Newton's first law: An object in motion tends to maintain its state of motion.

That is, if an object is at rest, it remains at rest unless acted on by a force. Likewise, an object moving in a straight line at constant speed tends to remain at that speed, and along that straight line, unless acted on by a force.

Q: So if a moving object tends to move in a straight line, how can I get something moving in a circle?

A: By supplying a force towards the center of the circle to cause a centripetal acceleration.

The centripetal acceleration is a vector that points towards the center of the circular path and represents the rate of change of velocity. Note that I said "velocity" and not "speed". The speed is constant along the circular path. So how does the velocity change without the speed changing? Remember that velocity is a vector quantity, so it has both magnitude and direction. If the direction changes, then the velocity changes, even though the magnitude (aka-the "speed") remains constant.

The centripetal acceleration of the particle is precisely that acceleration required to maintain the motion of a particle along a circular path at constant speed. As you have no doubt seen in your physics book, its magnitude is aC=v2/r.