The volume of a gas, such as helium or air, varies inversely with the pressure on it. If the volume of air is 325 cubic inches under a pressure of 11 psi, what pressure has to be applied to decrease the volume to 143 cubic inches?

Respuesta :

ANSWER

The pressure is 25 psi

STEP-BY-STEP EXPLANATION:

From the question provided, you can see that the relationship between the volume of a gas and the pressure is an inverse relationship.

The volume of a gas varies inversely with the pressure on it

This implies that as the volume of the gas increases the pressure of the gas decreases and vice versa.

The next thing is to assign variables

Let the volume of the gas be V

Let the pressure of the gas be P

Mathematically, this can be represented as

[tex]\begin{gathered} V\text{ }\propto\text{ }\frac{1}{P} \\ \text{Introduce a proportionality constant K} \\ V\text{ = }\frac{K}{P} \\ \text{Cross multiply} \\ K\text{ = VP -------- equation 1} \\ \end{gathered}[/tex]

The next step is to find the value of K from the given information in the question

• Volume = 325 cubic inches

,

• Pressure = 11 psi

Recall that, K = VP

K = 325 * 11

K = 3,575

Since you have gotten the value of K, then, you can now find your pressure when the volume Is 143 cubic inches

[tex]\begin{gathered} V=143inches^3 \\ K\text{ = 3,575} \\ K\text{ = VP} \\ \text{Divide both sides by V} \\ \frac{K}{V}\text{ = }\frac{VP}{V} \\ P\text{ = }\frac{K}{V} \\ P\text{ = }\frac{3575}{143} \\ P\text{ = 25 ps}i. \end{gathered}[/tex]

Hence, the pressure is 25 psi