Answer:
(ω₁ / ω₂) = 1.9079
Explanation:
Given
R₁ = 3.59 cm
R₂ = 7.22 cm
m₁ = m₂ = m
K₁ = K₂
We know that
K₁ = Kt₁ + Kr₁ = 0.5*m₁*v₁²+0.5*I₁*ω₁²
if
v₁ = ω₁*R₁
and
I₁ = (2/3)*m₁*R₁² = (2/3)*m*R₁²
∴ K₁ = 0.5*m*ω₁²*R₁²+0.5*(2/3)*m*R₁²*ω₁² <em>(I)</em>
then
K₂ = Kt₂ + Kr₂ = 0.5*m₂*v₂²+0.5*I₂*ω₂²
if
v₂ = ω₂*R₂
and
I₂ = 0.5*m₂*R₂² = 0.5*m*R₂²
∴ K₂ = 0.5*m*ω₂²*R₂²+0.5*(0.5*m*R₂²)*ω₂² <em>(II)</em>
<em>∵ </em>K₁ = K₂
⇒ 0.5*m*ω₁²*R₁²+0.5*(2/3)*m*R₁²*ω₁² = 0.5*m*ω₂²*R₂²+0.5*(0.5*m*R₂²)*ω₂²
⇒ ω₁²*R₁²+(2/3)*R₁²*ω₁² = ω₂²*R₂²+0.5*R₂²*ω₂²
⇒ (5/3)*ω₁²*R₁² = (3/2)*ω₂²*R₂²
⇒ (ω₁ / ω₂)² = (3/2)*R₂² / ((5/3)*R₁²)
⇒ (ω₁ / ω₂)² = (9/10)*(7.22/ 3.59)²
⇒ (ω₁ / ω₂) = (7.22/ 3.59)√(9/10)
⇒ (ω₁ / ω₂) = 1.9079
Answer:
The climate of the earth throughout history has always been <em><u>fluctuated between hot and cold periods. </u></em>
The statement "Good locations for turbines are limited" describes a drawback to wind energy.
Answer: Option B
<u>Explanation:</u>
Wind energy is one of the most useful and efficient renewable energy sources. But nothing is ideal in this universe and the same thing applies for wind energy also. The generation of electricity from wind energy requires setting up of turbines.
And these turbines can be set up in plane areas which is free from any disturbance except wind flow. In open area and flat plane surface only the turbines can rotate freely with the effect of wind.
But regions where the wind flow is minimum due to snow formation like the northern region of earth, the turbines cannot be set up there. So the locations for setting up of turbines are limited for good outcome in wind energy. This is one of the drawback of wind energy.
A horizontal line on a speed/time graph means a constant speed.
