energy question

[monokekie]

effenciency: 80%(coal burner)   98%(Electric hot water heater)  80% (Electric motor)    90% (Generator)  45%(Steam turbine)

The heat of combustion for tried brown coal is 30kj/g. How much electrical energy would be produced by a coal fired power station for each kilogram of dried brown coal consumed?

a 9.7kj
b 2.2 x 10^4 kj
3 1.1 x 10^4 kj
d 9.7 x 10^3 kj

how to do dis? any idea lol?

[arthurk]

Not sure, but from memory i dont think in coal fueled power stations there are any electric hot water heaters or electric motors
I know there is a coal burner, a generator and a steam turbine
so 30kj/g means 30000kj/kg then multiply by 0.8(coal burner) then 0.9 (generator) then 0.45 (steam turbine)
that will give you D i think
but don't trust my word for it haha