# Two point masses of mass 4m and m respectively separated by d distance are revolving under mutual force of attraction. Ratio of their kinetic energies

257 views
in Physics
closed
Two point masses of mass 4m and m respectively separated by d distance are revolving under mutual force of attraction. Ratio of their kinetic energies will be
A. 1 : 2
B. 1 : 5
C. 1 : 1
D. 1 : 2

by (67.4k points)

0 = 4m(-x)+m(d-x)
x=(d)/(5)
They will same omega
(K_(4m))/(K_(m))=((1)/(2)I_(4m)omega^(2))/((1)/(2)I_(m)omega^(2)) rArr (K_(4m))/(K_(m))=(I_(4m))/(I_(m))
(K_(4m))/(K_(m)) = ((1)/(2)(4m)(d//5)^(2))/((1)/(2)(m)(4d//5)^(2)) rArr (K_(4m))/(K_(m))=(1)/(4)