A car travels a distance of 540km in 6hours.What speed did he travel at?
1 answer:
You might be interested in
Answer:
a)23.4KW
b)12.11MW
c)1.155m^2
Explanation:
Hello!
To solve this problem follow the steps below
1. We will call 1 at the turbine entrance and 2 at the exit.
2. To calculate the change in kinetic energy, calculate the kinetic energy at the entrance and exit of the turbine and find the difference.
E=0.5mV^2
m=mass flow=12kg/s
E=kinetic energy
V=speed
solving
3. We find the enthalpies in states 1 and 2, and the density in the state 2 by thermodynamic tables
note: Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)
through prior knowledge of two other properties such as pressure and temperature.
h1=Enthalpy(Water;T=500C;P=4000kPa)
=3445KJ/kg
h2=Enthalpy(Water;x=0,92(quality);P=30kPa)=2438KJ/kg
density2=0.2078kg/m^3
4.
use the first law of thermodynamics that states that the energy entering the system is the same as the one that must go out, consider the flow energy, the work done and the kinetic energy
5.
to find the speed at the exit of the turbine we remember that the mass flow is defined as the product between the velocity density and the cross-sectional area
m=(density)(A2)V2