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A cylindrical 4.31 kg pulley with a radius of 0.294 m is used to lower a 6.27 kg bucket into a well. The bucket starts from rest and falls for 3.55 s. The acceleration of gravity is 9.8 m/[tex]s^{2}[/tex]

What is the angular acceleration of the cylindrical pulley?

Answer in units of rad/[tex]s^{2}[/tex]

Respuesta :

Answer:

[tex]24.81\ \text{rad/s}^2[/tex]

Explanation:

M = Mass of cylinder = 4.31 kg

R = Radius of cylinder = 0.294 m

m = Mass of bucket = 6.27 kg

g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]

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

a = Acceleration = [tex]\alpha R[/tex]

I = Moment of inertia of cylinder = [tex]\dfrac{MR^2}{2}[/tex]

The force balance of the system is

[tex]mg-T=ma\\\Rightarrow T=m(g-a)[/tex]

For the disk

[tex]TR=I\alpha\\\Rightarrow m(g-a)R=\dfrac{1}{2}MR^2\alpha\\\Rightarrow \alpha=\dfrac{g}{\dfrac{MR}{2m}+R}\\\Rightarrow \alpha=\dfrac{9.8}{\dfrac{4.31\times 0.294}{2\times 6.27}+0.294}\\\Rightarrow \alpha=24.81\ \text{rad/s}^2[/tex]

The angular acceleration of the pulley is [tex]24.81\ \text{rad/s}^2[/tex].