Question

A particle performs uniform circular motion in a horizontal plane. The radius of the circle is 20 cm. The centripetal force acting on the particle is 10 N. Its kinetic energy is 

(A) 0.1 J 

(B) 0.2 J 

(C) 2.0 J 

(D) 1.0 J

Answer 1

Answer is (D) 1.0 J

r = 20 cm = 20 x 10^-2 m = 0.2 m

Answer 2

Formula of Centripetal Force=mv^2/r

mv^2/r=10

mv^2=2                     (Change 20cm into 0.2m)

So,1/2mv^2=1   Ans