this is a question from HC Verma. I could solve it but am doubtful of my method. Here it is: A cube 4 cm is kept in a EMPTY cylinder of radius 3cm. Assuming the cube melts equally from all sides, find the length of the cube when it just leaves contact from the block.

leaves contact with the cylinder. sorry.

SOLUTION TO YOUR QUESTION :-

Let x be the edge of ice block.

When it just leaves the contact from the bottom of the cylinder then let h is the height of water melted from ice.

Since we know that :-

W=U

=> (x)cube X p(ice) X g = (x)sq X h X p(water) X g

Again volume of water formed from melting of ice is given by:-

(4)cube - (x)cube = pie X (r)sq X h - (x)sq X h (because amount of water =[pie X (r)sq - (x)sq]h)

=> 64- (x)cube = 9pie X h - (x)sq X h

Putting h = 0.9x

=> x = 2.26cm