The density of a person is slightly less than that of pure water. find the buoyant force of the atmosphere on a 60-kg person?

Question

explain how to solve the equation step by step to m understanding 

Answer 1

The buoyant force equals the weight of the displaced fluid, which in this problem is the displaced air.

 

V = volume of person

M = mass of person = 60 kg

 

Assume same density as that of water.

 

ρ_w = density of water = density of person (look up the density of water in your text book)

 

V = M/ρ_w

 

The volume of the person must equal the volume of the displaced air.

 

m = mass of the displaced air

 

ρ_a =  density of air, probably at sea level (look it up in your text book)

 

m = ρ_aV

 

g = acceleration of gravity

 

Weight of displaced air is

 

w = mg = (ρ_aV)g

 

That is the buoyant force F_B.  Put it all together and get

 

F_B = (ρ_aM/ρ_w)g = (ρ_a/ρ_w)Mg

 

Plug in the numbers.  You can finish from here.