Mechanics | 122651 - A wooden block floats in water in a sealed -askIITians

Amit Saxena Grade: upto college level

        A wooden block floats in water in a sealed container. When the container is at rest, 25% of the block the water. Consider the following five situations: (a) The container is lifted up at constant speed. (b) The container is lowered at constant speed. (c) The container is lifted up at an increasing speed. (d) The container is lowered at a decreasing speed. (e) The air pressure above the water in the container is increased. What happens in each situation?
(A) The block floats higher in the water.
(B) The block floats at the same level in the water.
(C) The block floats lower in the water.
(D) The fraction of the block above the water cannot be determined from the information given.

4 years ago

Answers : (1)

Navjyot Kalra

askIITians Faculty

654 Points

							(a) The correct option is (B).
According to Archimedes’ principle, the buoyant force acting on the wooden block is
F_B = v pg


(e) The correct option is (C).
When the air pressure above the water is increased, the force acting normally on the wooden block will also increase. This means the level of the block above the water will decrease. It will float lower in the water. Therefore, option (C) is correct.