Factor out the cos<span>θ:
</span>cosθ (2sin<span>θ + sqrt3) = 0
</span>Therefore, the only ways this can happen are if either cosθ = 0 or if (2sin<span>θ + sqrt3) = 0
</span>The first case, cosθ = 0 only at θ <span>= pi/2, 3pi/2.
</span>The second case, <span>(2sin<span>θ + sqrt3) = 0 simplifies to:
</span></span>sin<span>θ = (-sqrt3)/2
</span><span><span>θ = 4pi/3, 5pi/3
</span></span><span><span>Therefore the answer is A.
</span></span>
Can someone help me with this please and thanks !!
Answer:
Power generated = 4.315 kW
Step-by-step explanation:
Given,
- speed of wind when enters into the turbine, V = 12 m/s
- speed of wind when exits from the turbine, U = 9 m/s
- mass flow rate of the wind, m = 137 kg/s
According to the law of conservation of energy
Energy generated = change in kinetic energy
Since, the air is exiting at same elevation. So, we will consider only kinetic energy.
Energy generated in one second will be given by,


=4315.5 J
= 4.315 kJ
So, energy is generated in one second = 4.315 kJ
Power generated can be given by,

And the energy is generated is already in per second so power generated will be 4.315 kW.
Answer:
Denote the O, A, B, C, D as shown in attached image:
O is center of circle.
OA = OC = OD = radius of circle
=> triangle OAD is isosceles
=> BA = BD = 12.8
Applying Pythagorean theorem:
OB = sqrt(OA^2 - BA^2) = sqrt(15.1^2 - 12.8^2) = 8.0
=> x = OC - OB = 15.1 - 8.0 = 7.1
Hope this helps!
:)