Answer:
0.233
Explanation:
Given that
Diameter of rotor, d = 40 m
Power of rotor, P = 90 kW
Speed of the wind, v = 8 m/s
Density of air, p = 1.2 kg/m³
It is a known fact that
KE = ½mv², where mass flow rate, m
m = p.A.v, where Area, A
A = πd²/4
A = (3.142 * 40²)/4
A = 3.142 * 1600/4
A = 3.142 * 400
A = 1256.8 m², substitute for A in the mass flow rate equation
m = p.A.v
m = 1.2 * 1256.8 * 8
m = 12065.28, substitute for m in the KE equation
KE = ½mv²
KE = ½ * 12065.28 * 8²
KE = 12065.28 * 32
KE = 386088.96 W or
KE = 386.1 kW
Fraction of kinetic energy converted to electric energy is
Fraction = Electric Power / Total KE
Fraction = 90 / 386.1
Fraction = 0.233
net force is mass multiplied by acceleration. hope this helps
Answer:
Explanation:
Given:
mass of person, 
mass of merry go-round, 
radius of merry go-round, 
velocity of the person running, 
<u>We consider merry go-round as a ring:</u>
Now the moment of inertial of the ring is given as,
<u>Moment of inertia of the person considering as a point mass:</u>
<u>Now according to the conservation of angular momentum:</u>
where:
angular velocity of the merry-go-round
angular velocity of the person running
Answer:
Correct option a. one state variable T.
Explanation:
In the case of an ideal gas it is shown that internal energy depends exclusively on temperature, since in an ideal gas any interaction between the molecules or atoms that constitute it is neglected, so that internal energy is only kinetic energy, which depends Only of the temperature. This fact is known as Joule's law.
The internal energy variation of an ideal gas (monoatomic or diatomic) between two states A and B is calculated by the expression:
ΔUAB = n × Cv × (TB - TA)
Where n is the number of moles and Cv the molar heat capacity at constant volume. Temperatures must be expressed in Kelvin.
An ideal gas will suffer the same variation in internal energy (ΔUAB) as long as its initial temperature is TA and its final temperature TB, according to Joule's Law, whatever the type of process performed.
