A wind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. Its blades are 20 m in length. (a) What is the angular acceleration of the turbine? (b) What is the centripetal acceleration of the tip of the blades at t = 0 s? (c) What is the magnitude and direction of the total linear acceleration of the tip of the blades at t = 0 s?

Respuesta :

Answer:

-0.314 rad/s²

197.39 m/s²

197.49 m/s² and 1.822° counterclockwise.

Explanation:

[tex]\omega_f[/tex] = Final angular velocity

[tex]\omega_i[/tex] = Initial angular velocity

[tex]\alpha[/tex] = Angular acceleration

[tex]\theta[/tex] = Angle of rotation

t = Time taken

R = Radius = 20 m

[tex]\omega_i=0.5\times 2\pi\\\Rightarrow \omega_i=\pi[/tex]

[tex]\omega_f=\omega_i+\alpha t\\\Rightarrow \alpha=\frac{\omega_f-\omega_i}{t}\\\Rightarrow \alpha=\frac{0-\pi}{10}\\\Rightarrow a=-0.314\ rad/s^2[/tex]

Angular acceleration of the turbine is -0.314 rad/s²

Centripetal acceleration

[tex]a_c=\omega_i^2R\\\Rightarrow a_c=(\pi)^2\times 20\\\Rightarrow a_c=197.39\ m/s^2[/tex]

The centripetal acceleration of the tip is 197.39 m/s²

Tangential acceleration

[tex]a_t=\alpha R\\\Rightarrow a_t=-0.314\times 20\\\Rightarrow a_t=-6.28\ m/s^2[/tex]

Acceleration

[tex]a=\sqrt{a_c^2+a_t^2}\\\Rightarrow a=\sqrt{197.39^2+(-6.28)^2}\\\Rightarrow a=197.49\ m/s^2[/tex]

[tex]\theta=tan^{-1}\frac{|a_t|}{|a_c|}\\\Rightarrow \theta=tan^{-1}\frac{6.28}{197.39}\\\Rightarrow \theta=1.822^{\circ}[/tex]

Magnitude and direction of the total linear acceleration of the tip of the blades is 197.49 m/s² and 1.822° counterclockwise.

The angular acceleration of the turbine is -0.314 rad/s²

The centripetal acceleration of the tip of the blades at t = 0 s is 197.39 m/s²

The magnitude and direction of the total linear acceleration of the tip of the blades at t = 0 s are:

  • 197.49 m/s²
  • 1.822° counterclockwise

Calculations and Parameters:

  • wf= Final angular velocity
  • wt = Initial angular velocity
  • [tex]\alpha[/tex] = Angular acceleration
  • Ф= Angle of rotation
  • t = Time taken
  • R = Radius = 20 m

wt= 0.5 x 2[tex]\pi[/tex]

=>wf= wi + [tex]\alpha[/tex]t

= -0.314 rad/s^2

Then centripetal acceleration is

[tex]\pi[/tex]^2 x 20

= 197.39 m/s^2.

Then tangential acceleration is

[tex]\alpha[/tex]t= -0.314  x 20

= -6.28m/s^2

Read more about angular acceleration here:
https://brainly.com/question/25129606

ACCESS MORE