C E N 



Cor. 1. Hence V = VF x R or =. ~*^ ; 



/~R~ -2 T If 



and P -.= 5? v -p-, or . 



A'.r. I. If F varies as -=r or ~r (0 =: absolute force \ 

 \\-jt II* 



V = v --, and P ^ z . And in general if F varies as 



It (^2 



R 2 M - i ~ R 2 n - i ' ~ R n - i ' 9} 



E.v.2. If the body revolve at the earth's surface F g= 32^ feet, 



and R the earth's radius, .*. V V^r, and P = 2 * V . If the 



body revolve at any other distance x from the earth's centre, V = R 



Cor. 2. The same formulae are applicable to the centrifugal force ; 

 Hence if v velocity of the earth round its axis, and p time of its re- 



volving round its axis, centrifugal force at the equator -^-, ' or 



Ex. Centrifugal force at the Equator I centripetal ',". - : g ;* 

 R , g 



- 



2. Of the centripetal force of bodies revolving in any trajectories. ' 

 Let P V = chord of curvature passing through the centre of force, y 



radius vector, p perpendicular on the tangent, a area described dat, 



temp, then 



_ yg 4^p 



"IPV' ^-^"^"- 



E.r. 1. If a body revolve in an ellipse, (force tending to the centre) 



4 a* X C P 

 ~ A C* x"CB' 



C3 



