Water enters in a turbine at a speed of 500 m/s and leaves at 400 m/s. If `2 xx 10^(3)` kg/s of water flows and efficiency is 75%, then output power is

Options

A. `6.75xx10^(7) W`
B. 1000 KW
C. 100 KW
D. 400 W

Answer

a

Explanation

Here, change in K.E./sec.
`E=1/2mv_1^2-1/2mv_2^2`
=`1/2m(v_1^2-v_2^2)`
=`1/2xx2xx10^3[(500)^2-(400)^2]`
=`10^3xx10^4[25-16]`
=`9xx10^7 J//sec or walts`.
`:.` Real output power=`9xx10^7xx(75)/(100)=6.75xx10^7W`