A 0.400 mol sample of an ideal gas expands isothermally from T = 300 K and V = 1.00 L to V = 3.00 L. a) How much work does the gas do if the expansion is into an evacuated space (vacuum)?
b) How much work does the gas do if the expansion is done against an external pressure of 3.00 atm?
c) What is the maximum possible work done by the gas?
d) Draw a P-V sketch to illustrate parts a, b, and c in a similar fashion to Figs. 19.2 – 19.4 of the textbook

Afoot bridge is made as a simple deck, 4 m long, with a cross section 2 m (wide) and 20 cm thick, and made of wood. the deck is supported at the two ends. the maximum load allowable on the bridge is 10 tons, provided it is uniformly distributed on the deck. to sense this load, a strain gauge is placed at the center of the bridge and its resistance is monitored. if the sensor has a nominal resistance of 350 s2 and a gauge factor of 3.6, what is the reading of the strain gauge at maximum load? the modulus of elasticity for the wood used in the construction is 10 gpa.