Question

A) Consider a cubic fork floating on the surface of a pool. The sides of the cube are 1m long. Half of the cube is immersed in water as it floats. The density of the cork is 0.5 g/cm3. Determine the buoyant force on the cork.

B) What is the weight of the cork?

Answer 1

A) By Archimedes' principle the Buoyant force on the object is equal to the weight of water displaced by the object.

Volume of water displaced = .5 *1*1*1 =0.5 m³ , density of water = 1000 kg/m³ .

Therefore weight of water displaced = 500 kg.

Buoyant force =mg = 500*9.81 N = 4905 N

B) Volume of cork = 1*1*1 m³ = 1 m³ = (100)³  cm³ = 10⁶ cm³

density of cork = 0.5 g/cm³

Therefore mass = Volume * density = 5*10⁵ g =500 kg

weight = mg = 500*9.81 N = 4905 N.

This had to be the case as the buoyant force balances out the weight.

Answer =4905 N