Question

If a rubber ball of density $2gc{m}^{-3}$ thrown into a pool of a fluid and the fluid has a density of $4gc{m}^{-3}$, what will happen to the ball?

• A. Buoyant force pulls it inside.
• B. Density of the ball increases.
• C. It sinks in the fluid.
• D. It floats on the surface.

Answer 1

The correct option is D It floats on the surface.

If the density of the body is less than that of the fluid then the body floats (partially) on the surface. This is because the buoyant force is balanced by the weight of the body. If the density of the body is greater than that of the fluid then the body sinks in the fluid. In the above case, density of fluid is greater than the density of rubber ball, hence the rubber ball floats on the surface.