David Sang and Graham Jones Solutions for Chapter: Thermal Physics, Exercise 4: Questions

Use the first law of thermodynamics to answer the following.

 A gas is heated by supplying it with $250 \mathrm{kJ}$ of thermal energy; at the same time, it is compressed so that $500 \mathrm{kJ}$ of work is done on the gas. Calculate the change in the internal energy of the gas. 

Use the first law of thermodynamics to answer the following.

The same gas is heated as before with $250 \mathrm{kJ}$of energy. This time the gas is allowed to expand so that it does $200 \mathrm{kJ}$ of work on its surroundings. Calculate the change in the internal energy of the gas.

When you blow up a balloon, the expanding balloon pushes aside the atmosphere. How much work is done against the atmosphere in blowing up a balloon from a very small volume to a volume of $2$ litres $\left(0.002 {\mathrm{m}}^3\right)$? (Atmospheric pressure $= 1.0\times {10}^5 \mathrm{N} {\mathrm{m}}^{-2}.$)