Archimedes Principle Numericals

Archimedes' Principle states that:

• The weight of the fluid displaced by an object is equal to the weight of the object
• The volume of a solid is equal to the volume of the fluid it displaces
• The density of a fluid is equal to the density of the object submerged in it
• The buoyant force on an object is equal to the weight of the fluid displaced by the object

Buoyant force = ?

• Vdg

• V/g

• dg

• Vg/d

A body weighs 200gf in air and 180gf when completely immersed in water. What is the magnitude of the buoyant force?

• 200 N

• 0.2 N

• 2 N

• 20 N

Water is taken in a measuring cylinder. The volume reads 40 cc. An object of mass 100 g is immersed in the water with the help of a thin string. The water level now increases to 60 cc. Calculate the density of the object.

• 500 g/cm³

• 5000 kg/m³

• 500 kg/m³

• 50 g/cm³

An object of mass 10 kg is floating in water. What is the magnitude of the buoyant force?

• 10 N

• 2.5 N

• 100 N

• 80 N

A small box has a mass of 400 g and a volume of 300 cm³. What will be the weight of the box when it is immersed in water?   

• 100 N

• 1 N

• 10 N

• 5 N

When does an object sink?

• Weight < Buoyant force

• Weight > Buoyant force

• Weight = Buoyant force

When can a body float?

• density of body  >  density of liquid

• density of body  <  density of liquid

• density of body  =  density of liquid

A ball floats on water with 1/3rd of its volume outside water. What is the density of the ball?

• 700 kg/m³

• 990 kg/m³

• 667 kg/m³

• 200 kg/m³