Question

A slender homogeneous rod of length 2L floats partly immersed in water, being supported by a string fastened to one of its ends, as shown. The specific gravity of the rod is 0.75. The length of rod that extends out of water is: 

(A) L² 

(B) L²/2 

(C) L²/4 

(D) 3L²/4

Answer 1

Correct Option (A) L²

Explanation:

Let the length of rod that extends out of water is l₁ since the rod is in equilibrium 

So balancing net torque about point A