Answer to Question #249214 in Mechanical Engineering for russman

Question

A mass of air has an initial pressure of 1.3 MN/m ² , volume 0.014 and temperature 135 ⁰C. It is expanded until its final pressure is 275 kN/m ² and its volume becomes 0.056 m³ . Determine

a)The mass of air

b)The final temperature

Take R = 0.287 kJ/kg k

Answer 1

Given:-

Intial condition

P₁= 1300000 N/m²

V₁= 0.014 m³

T₁= 408 K

Final Condition

P₁= 275000 N/m²

V₂= 0.056 m³

To find :-

T₂= ?

mass (m)= ?

General gas equation

$PV= mRT$

By initial conditions

1300000*0.014 = 287 *m* 408

m= 0.156 Kg

By putting final Condition in general gas equation

=275000*0.056= 0.156* 287*T₂

T₂= 344 K