1 kg of air is heated at constant pressure from 200 oC to 800 oC. Calculate the change in internal energy if

a) The specific heat is assumed constant at its room-temperature value.

b) The specific heat is assumed constant at a value corresponding to that at the mid-point of the temperature range.

c) The specific heat is assumed to vary throughout the temperature range. Hint: Fit a curve to the table values to integrate.