Why does an object float or sink when placed on the surface of water?

Answer

If the density of an object is more than the density of the water, then it sinks.

This is because the buoyant force acting on the surface is less than the gravitational force acting on the surface.

If the density of an object is less than the density of the water, then it floats.

This is because the buoyant force acting on the surface is more than the gravitational force acting on the surface.

  1. Class 9
  2. Chapter 10 Class 9 - Gravitation (Term 2)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo