Plasticine learns how to swim

Well done! Your answer is right!

The illustration above shows what happens if you put the figure in the water. The figure floats on the water's surface!

The mass of the figure did not increase nor decrease compared to the ball before. But due to the reason that the figure is hollow inside, it displaces a lot more water than before. The amount of displaced water seems to be relevant for a floating or sinking body.

If this assumption is true, we will find out with the following experiment.