Two moles of a monoatomic ideal gas is confined in a container and is heated such that its temperature increases by $10\,^{\circ}C$. The approximate change in its internal energy is ..... $J$. $(R = 8.31\, J/mol\cdot K)$

Two cylinders $A$ and $B$ fitted with pistons contain equal number of moles of an ideal monoatomic gas at $400 \,K$. The piston of $A$ is free to move while that of $B$ is held fixed. The same amount of heat energy is given to the gas in each cylinder. If the rise in temperature of the gas in $A$ is $42 \,K$, what is the rise in temperature of the gas in $B$ (in $\,K$)? (Given $\gamma = 5/3$)

Starting at temperature $300 \; K,$ one mole of an ideal diatomic gas $(\gamma=1.4)$ is first compressed adiabatically from volume $V_{1}$ to $V_{2}=\frac{V_{1}}{16}.$ It is then allowed to expand isobarically to volume $2V_{2}.$ If all the processes are quasi-static,then the final temperature of the gas (in $K$) is (to the nearest integer):

Given below are two statements:
Statement $I:$ If heat is added to a system,its temperature must increase.
Statement $II:$ If positive work is done by a system in a thermodynamic process,its volume must increase.
In the light of the above statements,choose the correct answer from the options given below.

$A$ monatomic gas at a pressure $P$, having a volume $V$, expands isothermally to a volume $2V$ and then adiabatically to a volume $16V$. The final pressure of the gas is (Take $\gamma = 5/3$)

What are the differences between mechanics and thermodynamics?