Answer:
the buoyant force F will be 0.84 N
Explanation:
Assuming that a person has the density of water , then its volume could be calculated through
V= m/ρ , where m= mass of the person , ρ= density of water
then
V= m/ρ = 70 kg/ 1000 kg/m³ = 0.07 m³
then the buoyant force will be equal to the mass of displaced air in the volume V.
if we assume that the density of air in the atmosphere is ρa=1.225 kg/m³ then the buoyant force F will be
F= ρa*V*g = 0.07 m³*1.225 kg/m³ *9.8 m/s² =0.84 N