In Vol I,Chap 1-2 of the Feynman lectures on Physics,Feynman talks about how a change in pressure of a fixed amount of gas enclosed in a piston can cause its temperature to increase/decrease. He concluded by saying that:
"This means that when we compress a gas slowly,the temperature of the gas increases. So,under slow compression,a gas will increase in temperature,and under slow expansion it will decrease in temperature."
What is the significance of the word “slowly” in the above context? What is the difference when the compression/expansion isn’t done slowly but quickly instead?
On second thoughts,shouldn't the compression/expansion be done quickly so as to capture the temperature change before the heat gained is lost to the surroundings and vice versa for heat loss?