Question

the volume V of a fixed amount of a gas varies directly as the temperature T and inversely as the temperature P suppose that V=42 cm^3 when T=84 Kelvin and P=8 kg/cm^2 find the pressure when T=185 kelvin and V=74cm^3

Answer 1

Given data:

The expression for the volume is V=(kT)/P.

The given expression can be written as,

`\begin{gathered} k(T_1)/(P_1)=k(T_2)/(P_2) \\ (T_1)/(P_1)=(T_2)/(P_2) \end{gathered}`

Substitute the given values in the above expression.

`\begin{gathered} \frac{84\text{ K}}{8kg/cm^2}=\frac{185\text{ K}}{P_2} \\ P_2=17.619kg/cm^2 \end{gathered}`

Thus, the final pressure is 17.619 kg/cm^2.