A small block of wood is held completely immersed in (i) water, (ii) glycerine and then released. In each case, what do you observe ? Explain the difference in your observation in the two cases.

A sphere of iron and another of wood, both of same radius are placed on the surface of water. State which of the two will sink? Give reason to your answer.

It is easier to lift a heavy stone under water than in air. Explain.

What do you understand by the term upthrust of a fluid? Describe an experiment to show it's existence.