What determines whether an object sinks or floats in a liquid?

The correct answer is It's density.

Key Points

• The net upward force acting on any object in a fluid is called buoyant force.
  • The object will rise to the surface and float if the buoyant force is greater than its weight.
  • If the buoyant force is less than its weight then the object will sink.
  • Buoyancy is a force that acts on an object that causes it to rise or go up.
  • The Flotation and sinking of an object are dependent upon the relative density of each other.

Additional Information

• Density: It is defined as the mass of a body per unit volume. 
  • Dense material like Iron takes more mass in a given volume than wood.
  • Mathematically it gives a formula Density (ρ) = mass (m) / Volume (V)
    • SI Unit is kg/m³.
    • 1m³ = 1000 liters of water.
• Flotation: It can be defined as the tendency of an object to rise to the upper levels of the fluid or to stay on the surface of the fluid.
• Sinking: The opposite of floatation is sinking and can be defined as the tendency of an object to go to the lower levels of the fluid.