A wooden block is floating on water in a closed vessel. What will happen (i) if the air above the water is compressed, (ii) if all the air above the water is removed from the closed vessel?

A wooden block is floating on water in a closed vessel. What will happ

1.	A wooden block is floating on water in a closed vessel. What will happen (i) if the air above the water is compressed, (ii) if all the air above the water is removed from the closed vessel?
Answer» Solution :(i) If the air above the water in the closed vessel is compressed, the block will float UPWARDS some more. Here, WEIGHT of the wooden block = weight of displaced water + weight of displaced air. If the air is compressed, then its DENSITY increases and hence the weight of the displaced air increases while the weight of the displaced water decreases. Hence, the block will float upwards some more. (ii) If all the air above the water is REMOVED from the closed vessel, then the wooden block sinks more. This happens because when the air is removed, the buoyancy due to air is absent. Consequently, the apparentweight of the body increases, and the block sinks some more.