The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle `theta` should be

Options

A. `0^(@)`
B. `30^(@)`
C. `45^(@)`
D. `60^(@)`

Answer

B

Explanation

`-(df)/(Kf^(3))=dt" "," "-underset(f_(0))overset(f)(int)(df)/(Kf^(3))=underset(0)overset(t)(int)dt" ", " "-(1)/(K)underset(f_(0))overset(f)(int)f^(-3)df=timplies (1)/(2K)[(1)/(f^(2))-(1)/(f_(0)^(2))]=t`
`(1)/(f^(2))=(1+2f_(0)^(2)Kt)/(f_(0)^(2))" "," "f=(f_(0))/(sqrt(2f_(0)^(2)Kt+1))`