The pressure 45.0 meters under water is 543 kPa. What is this pressure in atm?

1 Answer
Oct 30, 2016

"5.28 atm"

Explanation:

Your task here is to convert from kilopascals, "kPa", to atmospheres, "atm", by using a conversion factor.

For starters, you should know that the pascal, "Pa", which is the SI unit for pressure, is defined as a force of "1 N" pressing down a surface of "1 m"^2

"1 Pa" = "1 N"/"1 m"^2

At sea level, the molecules of air that make up the atmosphere press down on each square meter with a force of "101325 N", which basically means that at sea level, the atmospheric pressure is equal to

"101325 N"/"1 m"^2 = "101325 Pa"

This is also defined as one standard atmosphere, which means that you have

"1 atm " = " 101325 Pa"

Since you know that

"1 kPa" = 10^3"Pa"

you can say that you have

color(purple)(bar(ul(|color(white)(a/a)color(black)("1 atm " = " 101.325 kPa")color(white)(a/a)|)))

This is your conversion factor. You can use it to say that the pressure at "45.0 m" below surface level is equal to

535 color(red)(cancel(color(black)("kPa"))) * "1 atm"/(101.325color(red)(cancel(color(black)("kPa")))) = color(green)(bar(ul(|color(white)(a/a)color(black)("5.28 atm")color(white)(a/a)|)))

The answer is rounded to three sig figs.