## Essential University Physics: Volume 1 (4th Edition)

a) We know that the pressure will decrease to 75 kPa, which is .75 of the original pressure. According to the ideal gas law, the pressure and the volume of the balloon are inversely proportional, so it follows: $=\frac{1}{.75}=1.33$ b) We know that the work is given by: $W =-nRTln(c)$ Where c is a constant that we name in order to represent the fraction found in part a. Using this, we find: $W =-(.3)(8.314)(300)ln(1.33 )\approx 220 \ J$