Write the equation for the work done during the compression of an ideal gas.

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(N/A) The work done $W$ by or on a gas during a process is given by the integral $W = \int_{V_i}^{V_f} P \, dV$.
For an ideal gas undergoing an isothermal compression,the equation is $W = nRT \ln\left(\frac{V_f}{V_i}\right)$. Since it is compression,$V_f < V_i$,making $W$ negative (work done on the gas).
For an adiabatic compression,the equation is $W = \frac{nR(T_f - T_i)}{\gamma - 1} = \frac{P_f V_f - P_i V_i}{\gamma - 1}$,where $\gamma$ is the adiabatic index.

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$(C)$ An ideal monoatomic gas expands to twice its original volume such that its pressure $P \propto V^{-4/3}$$(r)$ The gas loses heat
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Three processes compose a thermodynamic cycle shown in the $PV$ diagram. Process $1\rightarrow 2$ takes place at constant temperature. Process $2\rightarrow 3$ takes place at constant volume,and process $3\rightarrow 1$ is adiabatic. During the complete cycle,the total amount of work done is $10\,J$. During process $2\rightarrow 3$,the internal energy decreases by $20\,J$ and during process $3\rightarrow 1$,$20\,J$ of work is done on the system. How much heat is added to the system during process $1\rightarrow 2$ (in $,J$)?

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