Question

a heavy rock is lying under water on the bottom of a swimming pool. which of the following is correct? your response history: 1. incorrect. your answer: c. it requires no more force to lift a rock under water than it does on dry land, and also it requires no less force--the situation is the same in either case. score: 0/0.2 you may change your answer and resubmit: a. the rock is harder to lift when it is under water than it would be on dry land because the water pressure pushing down on it helps hold it down. b. the rock is easier to lift when it is under water than it would be on dry land because the buoyant force of the water pushing on the rock helps to push it upward. c. it requires no more force to lift a rock under water than it does on dry land, and also it requires no less force--the situation is the same in either case. d. the rock is significantly easier to lift when it is under water because its actual weight is less in water--the earth pulls on it differently. e. the rock is significantly harder to lift when it is under water because the buoyant force acts in addition to its weight, making a greater force necessary.

Explanation:

According to Archimedes' principle, when an object is submerged in a fluid, it experiences an upward - buoyant force. This buoyant force reduces the effective weight of the object that needs to be lifted. So, it is easier to lift a rock underwater than on dry land.

Answer:

B. The rock is easier to lift when it is under water than it would be on dry land because the buoyant force of the water pushing on the rock helps to push it upward.