For nitrogen, plot how the internal energy (U) varies with T within the range 25oC - 1000oC

Question:

For nitrogen, plot how the internal energy (U) varies with T within the range 25oC - 1000oC while the pressure is held constant at 100 kPa. Use
(a) The PG model.
(b) The IG model.
(c) What-if Scenario: Would any of the plots change if the pressure were 1 MPa instead?