Question

Mr. X works in a store which sells tyres. One cold evening when Mr. X was working alone, he accidentally got locked in the basement where all the tyres were stored. Since no one could help him till the next morning, he wanted to somehow warm the basement. To do so he decided that he will burst the tyres which (filled with air), causing explosions, which he thought will release hot air, and keep him warm.

Will Mr.X's idea work?

• A. It will work!
• B. Mr. X has got it dead wrong. Bursting tyres will make the basement colder
• C. Bursting the tyres would release air at the same temperature. All Mr. X would do is destroy good tyres.
• D. Need more information about the type of tyre he planned to burst

Answer 1

The correct option is B

Mr. X has got it dead wrong. Bursting tyres will make the basement colder

When a tyre bursts the pressurized air inside the tyre expands rapidly. Such a rapid expansion of the gas in a system is called adiabatic expansion.
In an adiabatic expansion process the change in the state of the gas happens so quickly that there is no time for any heat transfer to happen between the system and the environment.
$\Rightarrow Q=0$.
Therefore from first law of thermodynamics it follows that
$\Delta E_{int}=-W$.
Whenever the gas is expanding in a system the work done by the gas is going to be positive so the change in $E_{int}$ will be negative implying that there will be a drop in temperature.
So when Mr. X. bursts the tyre it is going to release cold air into the room, making it more uncomfortable for him.