Can someone please explain how to do this problem? A primitive jet engine is fix

Question

Can someone please explain how to do this problem?

A primitive jet engine is fixed to a stationary test rig. The engine has an inlet area of Ai = 2.5 m2 and an outlet area of Ao = 0.5 m2. Ambient air (Ti, = 298 K, P = 101 kPa) enters the engine at a flow rate of mi = 10 kg s-1. Fuel with a heating value of qf = 43 MJ kg-1 flows into the engine at deltam, = 0.1 kg s-1, and is mixed with the air and combusted. Determine the thrust produced by the engine. Note: you may assume that the air and air-fuel mixture arc perfect gases with: R = 287 J kg-1 K-1, cp = 1005 J kg-1 K-1

Explanation / Answer

thrust produced= (mi+delm)*vf-mi*vi

now volume flow rate at inlet

V=10*0.287*298/101

=8.46 m^3

vi=V/A

=16.93 m/s

enthalapy change =change in the kinetic energy

=43*0.1

=4.3 MJ

so final kinetic energy/time

=1/2*10*16.93^2+4.3*10^6

=4.301*10^6 J

final velocity

=2796.56 m/s

so F=(mi+delm)*vf-mi*vi

=28076.02 N ans

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