10-4: Atmospheric Pressure And Gauge Pressure

Question 1

What is pressure?

Answer 1

pressure is the physical force exerted on an object

pressure is the force applied perpendicular to the surface
of an object per unit area

p = F/A

Question 2

Atmospheric pressure

Answer 2

The pressure due to the weight of the atmosphere is
exerted on all objects immersed in this great sea of air
including our bodies.

Question 3

The pressure of the Earth atmosphere, as in any fluids, changes with depth and density.
But the earth atmosphere is somewhat complicated. Why?

Answer 3

There is no specific top surface to the atmosphere to measure the depth

Density varies with altitude

Question 4

Patm = atmospheric pressure

1 atm?

Answer 4

1.013x105 Pa or 1.013x105 N/m2

Question 5

How does human body withstand the

enormous pressure?

Answer 5

The living cells maintain an internal pressure that closely equals the external pressure just as the pressure inside a balloon closely matches the outside pressure of the atmosphere

Question 6

Gauge pressure

Answer 6

The difference between the total pressure and the Atmospheric pressure

P gauge = p total – patm

Question 7

Absolute Pressure

Answer 7

is the sum of atmospheric pressure and and the gauge pressure

pabs = patm + Pgauge

Question 8

Height:

Answer 8

P abs= 1.013x105 + (density X h Xg)

Question 9

pascal

Answer 9

P abs= 1.013x105 + P gauge

Question 10

Kpa

Answer 10

P abs= 101.3 + P gauge