When a tyre bursts, the air coming out is cooler than the surrounding air. Explain.

We know that pressure inside the tyre is greater than the atmospheric pressure of surroundings. So, when a tyre bursts there is an adiabatic expansion of the air (adiabatic because no heat is either supplied or released during expansion). In the expansion process, work is done by the gas. Now work done in an adiabatic process is given as


Where =number of moles


R=gas constant


T1=initial temperature


T2=final temperature


= ratio of specific heat at constant pressure and volume


Since work is done by the gas in adiabatic expansion, therefore, W>0. From equation (i), for W>0, T1>T2. This means that air


coming out of tyre will be at a lower temperature than when it was inside the tyre.


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