1. The problem statement, all variables and given/known data The cannon is made from V=30ml test tube completely closed with a plug (diameter d=1,5cm; length l=3cm; mass m=5g). Before closing the test tube, V'=1ml of water is poured into it. Room temperature is 20oC , pressure p=105 Pa , relative humidity is σ=20%. When the temperature in the test tube becomes t'=40oC the plug is shot. I need to find how much the escaping gas has increased the speed of the plug after it had been shot. I know that the initial speed with which the plug starts to move is v=12.134m/s. 2. Relevant equations Ideal gas laws. 3. The attempt at a solution Vplug=πr2=5.3 cm3 Vfree space=30ml-5.3ml=24.7ml I know that: t/Vfree space=t'/V What now?