A large wind turbine has three blades
connected to a central hub. Each blade
is 50.0 m long and rotate at 10.0 rpm.
(a) What is the angular speed ?
(b) What is the linear speed of the tip?
(c) Suppose it take 10.0 min to stop
rotating from full speed. What is
the stopping angular acceleration a?

Respuesta :

Answer:

Part a)

Angular speed of the turbine is given as

[tex]\omega = \frac{\pi}{3} rad/s[/tex]

Part b)

Linear speed of the tip is given as

[tex]v = 52.35 m/s[/tex]

Part c)

Angular acceleration is given as

[tex]\alpha = -1.75 \times 10^{-3} rad/s^2[/tex]

Explanation:

As we know that the frequency of rotation of blade is given as

[tex]f = 10 rpm[/tex]

Part a)

Angular frequency is given as

[tex]\omega = 2\pi f[/tex]

[tex]\omega = 2\pi(\frac{10}{60})[/tex]

[tex]\omega = \frac{\pi}{3} rad/s[/tex]

Part b)

Linear speed of the tip of the blade is given as

[tex]v = r\omega[/tex]

[tex]v = 50(\frac{\pi}{3})[/tex]

[tex]v = 52.35 m/s[/tex]

Part c)

As it comes to stop after t = 10 min

so by equation of kinematics we will have

[tex]\omega = \omega_0 + \alpha t[/tex]

[tex]0 = \frac{\pi}{3} + \alpha (600)[/tex]

[tex]\alpha = -1.75 \times 10^{-3} rad/s^2[/tex]