Question

Which situation has the greatest pressure? A. Atmospheric pressure at sea level, equal to 1.01 X 105 N/m2 B. The pressure that a person of mass 70 kg exerts on the floor when she balances on the ball of one foot, with an area of contact of 50 cm2 C. The pressure that a physics textbook of mass 2.5 kg exerts on a desk when it is lying flat on the desk, with an area of contact of 22 cm X 28 cm
(a) Identify the empirical formula of this compound.

Answer 1

Answer:

B

Explanation:

We are given that

A.Atmospheric pressure=$P_0=1.01\times 10^5N/m^2$

B.Mass,m=70 kg

Area,A=$50 cm^2=50\times 10^{-4} m^2$

$1 m^2=10^4 cm^2$

Force=mg

Where $g=9.8 m/s^2$

Using the formula

$F=70\times 9.8=686 N$

$P=\frac{F}{A}=\frac{686}{50\times 10^{-4}}=1.37\times 10^5 N/m^2$

C.Mass ,m=2.5 kg

Area,A=$22\times 28=616 cm^2=616\times 10^{-4} m^2$

Pressure=$\frac{mg}{A}=\frac{2.5\times 9.8}{616\times 10^{-4}}=397.7 N/m^2$

In situation B has greatest pressure.