One mole of an ideal monatomic gas goes from a to c along the diagonal path. The scale of the vertical axis is set by pab=4.0 kPa and pc=2.0 kPa, and the scale of the V axis is Vbc=6.0 m3 and Va=3.0 m3. (a) what is the change in the internal Energy? (b) How much Energy is added to the gas? (c) How much heat is required if the gas goes from a to c via abc?