When an object is immersed in a fluid, Buoyancy is the upward force exerted on the object by the fluid. According to the Archimedes principle, the magnitude of the upward force is equal to the weight of the fluid displaced. Buoyancy calculator is an instant online tool which can easily find the buoyancy on object given its respective parameters.
Example 1: A spherical object of mass 500g and radius 0.2m is held fully under water. Calculate the buoyant force(FB) exerted on the object.
Mass = 500g Weight = m * g = (500/1000)kg * 9.8m/sec2
Weight of the object=1.96N
Volume of water displaced=Volume of the object (since it’s held fully under) = 4/3*π * r3= 0.0335m3
Buoyant force = Weight of the water displaced
FB= (mass of water)*g = (Density of water)*(Volume of water displaced)*g
FB = (1000kg/m3) * (0.0335m3) * (9.8m/sec2) = 328N
Example 2: In the above given example, when the object is released will it sink to the bottom or float on the water surface?
The buoyant force or the upward force acting on the object is 328N.
The weight exerted by the object is 1.96N which is the gravitational pull of the object downward.
Since the upward buoyant force Weight of the object downward
Hence the object will rise to the surface of the water and float!