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Question
A plastic cube is released into the water. Will it sink or come to the surface of the water?
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Solution
When a plastic cube is released into water, it will come to the surface and float if its density is lower than the density of water. This happens because of buoyancy. Water exerts an upward buoyant force on the cube, and if this force is equal to or greater than the cube’s weight, the cube floats.
In this experiment, the plastic cube floats because it is less dense than water. In contrast, a glass cube usually sinks because its density is greater than that of water, so its weight is greater than the buoyant force acting on it.
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