Peoples Physics Book Version-2

7.3. Characterizing The Force and Motion http://www.ck12.org

7.3 Characterizing The Force and Motion

If a massmis traveling with velocity~vand experiences a centripetal —always perpendicular — force~Fc, it will
travel in a circle of radius

r=

mv^2

|~F|

[1]

Alternatively, to keep this mass moving at this velocity in a circle of this radius, one needs to apply a centripetal
force of

F~c=mv

2

r

[2]

By Newton’s Second Law, this is equivalent to a centripetal acceleration of:

~Fc=ma~c=mv

2

r

[3]