(Hopefully) simple thermodynamics question

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Compressing an ideal gas in a thermally isolated piston results in an increase in temperature. The internal energy change (ΔU) is positive due to work being done on the gas, leading to a rise in temperature (ΔT > 0). This temperature increase occurs because the compression raises the kinetic energy of the gas molecules, akin to the effect of striking a tennis ball with a racket. The relationship between internal energy, heat, and work explains this phenomenon clearly. Therefore, the gas temperature indeed rises during compression.
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Suppose you have a piston of ideal gas that's thermally isolated from its surroundings. You compress the gas by pushing down on the piston. Question: Does the temperature of the gas change, and why?

My answer: YES, it changes. Since \Delta U = Q + W, and work was done ON the gas (by compressing it), \Delta U > 0. Since the energy of an ideal gas is only dependent on the temperature of the gas, this implies \Delta T > 0.
 
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Yes, it is increasing because with the piston you increase the momentum of the molecules that are bouncing of it, increasing their speed and with that their kinetic energy, that is like hitting a tennis ball with a racket.
You see the equation in the right way.
 

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