Thermodynamics question

Air is flowing in a duct. At station 1, the temperature is measured to be 46C, while at station 2 downstream the temperature probe measures 34C. a) Determine the change in flow energy per unit mass. b) If the diameter of station 1 is twice as big as the diameter of station 2, and the pressure at station 2 is 20% lower than at station 1, find the flow velocity ratio V2/V1 (assume steady state operation)