The Bicycle Pump - Answer

The Bicycle Pump - Answer = B

Answer: The correct answer is B. While friction, both by the mechanical pump action and air molecule collisions, adds some small amounts of heat, the main effect is that the pumping process is basically an adiabatic (no heat loss) process. That is, the pumping takes place over a short enough period of time that effectively no heat is lost to the outside. Therefore the work done compressing the gas goes into the change in internal energy of the gas. The internal energy of the gas is proportional to the absolute temperature. So as the internal energy increases so does the temperature of the gas which in turn heats the pump and the valve.

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