If there was less of an atmosphere above Earth, then __________________. a. the
ID: 109180 • Letter: I
Question
If there was less of an atmosphere above Earth, then __________________.
a.
the air we breathe would be more dense and there would be more air pressure
b.
the air we breathe would be less dense and there would be more air pressure
c.
the air we breathe would be less dense and there would be less air pressure
d.
None of the above are correct.
a.
the air we breathe would be more dense and there would be more air pressure
b.
the air we breathe would be less dense and there would be more air pressure
c.
the air we breathe would be less dense and there would be less air pressure
d.
None of the above are correct.
Explanation / Answer
c. The air we breathe would be less dense and there would be less air pressure.
Pressure is equal to the force acting on an object divided by the area upon which it is acting. The pressure exerted by an air mass therefore depends on the mass of the air and on the area below the mass. For a given air column, if the density of the air increases then the pressure exerted on the surface by the air column also increases. That is, of course, because the higher density means that the air column has greater mass and exerts a greater force on the area below it.