P.O.E Presentation
Greje R. Abangan II-BSPT
Predict
v What will happen to the can if we invert and put the soda-pop can into a pan of water?
v Will it explode, expand, compress, or stay the same?
v Predict
Observe:
v Put a small amount of water in an aluminum soda-pop can and heat it on a stove until steam comes out from the opening.
v Then, with a pair of tongs, quickly invert the can into a pan of water.
v Observe
Explain
As we heat a small amount of water in aluminum soda-pop can and as steam comes out of the opening, the air inside has been driven out and replaced by steam.
The can is crushed by the atmospheric pressure. Why? When the molecules of steam encounter water from the pan, condensation occurs, leaving a very low pressure in the can, whereupon the surrounding atmospheric pressure crunches the can. Here we see how pressure is reduced by condensation. This is why in a heat engine the role of condensation in the turbine plays crucial. Without the temperature difference, the turbine won’t run and do work. Remember that temperature is dependent upon the pressure of the system.
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