Question

Give reason for the following:
(a) On driving the scooter for a long time, the air pressure in
the tyres slightly increases.
(b) In an isothermal process there is no change in internal
energy of an ideal gas.
(c) When air of atmosphere rises up, it cools.

Answer 1

Dear Student,
a.
During driving, as a result of the friction between the tyre and the road, the temperature of the tyre and the air inside it, increase since volume of the tyre does not change (practically); due toincrease in temperature the pressure of the gas inside the tube increases.
$$\begin{gathered} b.snceinisothermalprocessTemperatureincons\tan t \\ henceinternlaenergytotallydependsuponthetemperature \\ U=\frac{nfRT}{2}henceUremainscons\tan t. \\ c.aswemoveupwardthepressuredecreaseshenecthetemperaturedecreases \\ Regards \end{gathered}$$