Why Do Some Things Float and Others Sink?

Some things float because they are lighter than water, and others sink because they are heavier. Imagine you're in a bathtub. If you drop a rubber duck in the water, it floats because it’s not as heavy as the water it pushes aside. But if you drop a rock, it sinks because it's much heavier than the water it displaces.

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Examples

  1. A rubber duck floats because it’s light compared to the water.
  2. A stone sinks because it is denser than the water.
  3. Your body floats in a pool if you keep your lungs full of air.

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