Question

When air is pumped into a cycle tyre the volume and pressure of the air in the tyre both are increased. What about Boyle’s law in this case?

Answer 1

From ideal gas equation, $PV=\mu RT$

For Boyle’s law, at same $T$ and $\mu$,

$P\propto \frac{1}{V}$

When air is pumped, more molecules are pumped in. Boyle’s law is stated for situation where number of molecules remain constant.

So, when air is pumped into a cycle tyre, the volume and pressure of the air in the tyres both are increased.

$\text{Final Answer}:$

When air is pumped, more molecules are pumped in. Boyle’s law is stated for situation where number of molecules remain constant.