Please read my question properly I dont want an answer for the question below. I

Question

Please read my question properly I dont want an answer for the question below. I want you to explain to me why I get 2 different answers when I solve it 2 different ways.

Steam at 1.8 MPa and 400?C steadily enters a nozzle whose inlet area is 0.02 m2. The mass flow rate of steam through the nozzle is 5 kg/s. Steam leaves the nozzle at 1.4 MPa with a velocity of 275 m/s. Heat losses from the nozzle per unit mass of the steam are estimated to be 2.8 kJ/kg. Determine (a) the inlet velocity

When I solve it using the fomula below I get this answer.

However, when I solve it by finding the density with PV = mRT

Density = P/RT

and then using mflow rate = Density x Vave x Ac   I get a different answer. Can the question above be solved both ways?

Explanation / Answer

First method is correct and steam is not an ideal gas, so ideal gas equation can not be applied here.

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