The internal energy change in a system that has absorbed $2 \, kcal$ of heat and done $500 \, J$ of work is ...... $J$.

In how many ways can the internal energy of a system be changed?

Consider one mole of perfect gas in a cylinder of unit cross-section with a piston attached as shown in the figure. $A$ spring (spring constant $k$) is attached (unstretched length $L$) to the piston and to the bottom of the cylinder. Initially,the spring is unstretched and the gas is in equilibrium. $A$ certain amount of heat $Q$ is supplied to the gas,causing an increase in volume from $V_0$ to $V_1$.
$(a)$ What is the initial pressure of the system?
$(b)$ What is the final pressure of the system?
$(c)$ Using the first law of thermodynamics,write down a relation between $Q, V_0, V_1, P_a$ and $k$.

$A$ thermodynamic system absorbs $2 \, kcal$ of heat and performs $500 \, J$ of work. The change in its internal energy is ......... $J$.

The first law of thermodynamics is a special case of which law?

When $110 \ J$ of heat is supplied to a system and the change in internal energy is $40 \ J$,the work done is .......... $J$.