With what force the air presses on the palm of the hand with an area of 50 cm2 at a pressure of 750 mm Hg. Art.

S = 50 cm ^ 2 = 0.005 m ^ 2.
h = 750 mm = 0.75 m.
g = 9.8 m / s ^ 2.
ρ = 13500 kg / m ^ 3.
F -?
Pressure is the force calculated per unit area p = F / S.
F = p * S.
The hydrostatic pressure of a column of mercury in a barometer is equal to atmospheric pressure.
P = ρ * g * h.
F = ρ * g * h * S.
F = 13500 kg / m ^ 3 * 9.8 m / s ^ 2 * 0.75 m * 0.005 m ^ 2 = 496 N.
Answer: air presses on the hand with a force of F = 496 N.