Centripetal Force
Centripetal Force = The push
or pull on a moving object toward the center of its curved path. Centripetal
force is always a net force.

Centripetal
force keeps the planets in orbit. According toNewton’s
1^{st} law, all masses have inertia and would like to move at
constant speed in a straight line. These objects have momentum. Earth wants
to move straight but it is prevented from doing so due to the sun’s gravity.
The sun applies a centripetal force. 



When
you spin a bucket of water over your head without spilling a drop, you are
also applying a centripetal force. If you
let go of the bucket, it will move in a straight line. 


Centripetal force pulls the plane toward the center of the
circle. The plane’s inertia and momentum make it want to fly straight. 

While the coaster cars zoom around the loop,
the track exerts a centripetal force toward the center of the loop.