A diatomic gas is heated at constant pressure. If `105J` of heat is given to the gas, find (a) the change in internal energy of the gas (b) the work done by the gas.

Explanation

Suppose the volume changes from `V_(1)` to `V_(2)` and the temperature changes from `T_(1)` to `T_(2)` The heat supplied is
`DeltaQ = DeltaU +P DeltaV = DeltaU +nRDeltaT = DeltaU +(2DeltaU)/(t) [DeltaU =(nfRDeltaT)/(2)]`
(a) The change in internal energy is
`DeltaQ = DeltaU [1+(2)/(f)]`
`105 = DeltaU [1+(2)/(5)], DeltaU = 75 J`
(b) The work done by the gas is
`W = DeltaQ - DeltaU = 105J - 75J = 30J`.