Question

A blimp floats because it is filled with helium gas (He) which has a smaller molecular mass than air (in g/mol). Helium can lift objects because it exhibits a buoyant force equal to the difference in grams/mol. At room conditions (P = 1 atm, T = 25 degrees Celsius) what volume of helium would lift a pound?(A) 611 L(B) 37.3 L(C) 444 L(D) 2777 L

Answer 1

Answer:

444 L

Explanation:

According to Archimedes the buoyancy force  is equal to the weight of the displaced substance. In this case, the displaced substance is Air. So to calculate the lifting power of Helium, start with the weight of air in volume

Since the Helium itself has weight, we need to use the difference in density between air and helium.

We know that the density of air is 1.2 $kg/m^3$

Density of Helium is 0.1787  $kg/m^3$

To lift a object of 1 pound  which is equal to 0.453 kg we need $\frac{0.453}{1.2-0.1787}=0.444$ $m^3$ helium There is 1000 liters in a $m^3$

So the required volume of helium= 0.444×1000=444 L