Question

A rectangular block is 5 cm $\times$ 5 cm $\times$ 10 cm in size. The block is floating in water with 5 cm side vertical. If it floats with 10 cm side vertical, what change will occure in the level of water?

• A. No change
• B. It will rise
• C. It will fall
• D. It may rise or fal I depending on the density of block

Answer 1

The Correct Option is A

By the law of floatation, we know that a body will float in a liquid, when its weight W is equal to the weight w of the liquid displaced by the immersed part of the body. But this does not necessarily indicate that the body will be in equilibrium. A body will be in equilibrium only, if the resultant of all the forces and couples acting on the body is zero. If W and w act along different lines, they will form a couple which will tend to rotate the body. Thus, a floating body can be in equilibrium, if no couple acts on it. It will be so. if the line of action of If W and w act along the same vertical straight line. Here, in both the situations, as the mass of floating block remains same, hence according to principle of floatation mass of volume of water displaced also remains same. Hence, water level will remain same in both the cases.