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Consider a bicycle wheel to be a ring of radius 30 cm and mass 1.5 kg. Neglect the mass of the axle and sprocket. If a force of 22 N is applied tangentially to a sprocket of radius 6 cm for 6 s, what angular speed does the wheel achieve, assuming it rolls without slipping?

Respuesta :

Answer:

The angular speed after 6s  is [tex]\omega = 1466.67s^{-1}[/tex].

Explanation:

The equation

[tex]I\alpha = Fd[/tex]

relates the moment of inertia [tex]I[/tex] of a rigid body, and its angular acceleration [tex]\alpha[/tex], with the force applied [tex]F[/tex] at a distance [tex]d[/tex] from the axis of rotation.

In our case, the force applied is [tex]F = 22N[/tex], at a distance [tex]d = 6cm =0.06m[/tex], to a ring with the moment of inertia of [tex]I =mr^2[/tex]; therefore, the angular acceleration is

[tex]$\alpha =\frac{Fd}{I} $[/tex]

[tex]$\alpha =\frac{22N*0.06m}{(1.5kg)*(0.06)^2} $[/tex]

[tex]\alpha = 244.44\: s^{-2}[/tex]

Therefore, the angular speed [tex]\omega[/tex] which is

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

after 6 seconds is

[tex]\omega = 244.44$\: s^{-2}* 6s[/tex]

[tex]\boxed{\omega = 1466.67s^{-1}}[/tex]