What is the weight in pounds of the air in rectangular room of volume 3.39xx10^5 " ft"^3, given the density of air is rho_"air"=1.29 " kg"/"m"^3?

1 Answer
Mar 20, 2016

The weight is 2.74xx10^4 " lbs", which is a little more than the typical large elephant!

Explanation:

First, convert the cubic feet of the room into cubic meters.

3.39xx10^5 " ft"^3 = 3.39xx10^5 " ft"^3 * ((1 " m")/(3.281 " ft"))^3approx 9,600 " m"^3

Next, solve the formula for density for mass (in kg).

rho_"air"="mass"/"volume"

"mass "=rho_"air"xx"volume"
"mass "=1.29 " kg"/"m"^3xx9,600 " m"^3
"mass "=12,384" kg"=1.24xx10^4

Now, using the fact that 1 " kg"=2.21 " lbs", you can find the weight in pounds.

"mass "=1.24xx10^4" kg"xx(2.21 " lbs")/(1 " kg")=2.74xx10^4 " lbs"