The volume of a gas in a container varies inversely as the pressure on the gas. If a gas has a volume of 248 cubic inches under a pressure of 5 pounds per square inch what will be its volume of the pressure is increased to 7 pounds per square inch? Round your answer to the nearest integer if necessary.

Respuesta :

If two quentities (V, P) are very inversely, so

[tex]\begin{gathered} V=\frac{k}{P} \\ OR \\ \frac{V_1}{V_2}=\frac{P_2}{P_1} \end{gathered}[/tex]

Where k is the constant of variation, we can get it by using the initial values of V and P

Let us use the second rule

Since V is 248 cubic inches when P is 5 pounds per square inch, then

[tex]\begin{gathered} V_1=248 \\ P_1=5 \end{gathered}[/tex]

We need to find V when P = 7 pounds per square inch

[tex]\begin{gathered} V_2=? \\ P_2=7 \end{gathered}[/tex]

Let us substitute these values in the second rule

[tex]\frac{248}{V_2}=\frac{7}{5}[/tex]

By using cross multiplication

[tex]\begin{gathered} V_2\times7=248\times5 \\ 7V_2=1240 \end{gathered}[/tex]

Divide both sides by 7

[tex]\begin{gathered} \frac{V_2}{7}=\frac{1240}{7} \\ V_2=177.142857 \end{gathered}[/tex]

Round it to the nearest integer

[tex]V_2=177in^3[/tex]

The volume of the gas is 177 cubic inches