contestada

A uniform, solid metal disk of mass 6.10 kgkg and diameter 30.0 cmcm hangs in a horizontal plane, supported at its center by a vertical metal wire. You find that it requires a horizontal force of 4.29 NN tangent to the rim of the disk to turn it by 3.40 ∘∘, thus twisting the wire. You now remove this force and release the disk from rest.

Respuesta :

Answer:

10.84406 Nm/rad

0.068625 kgm²

2.00066 rad/s

0.49983 s

Explanation:

F = Force = 4.29 N

R = Radius = [tex]\dfrac{30}{2}=15\ cm[/tex]

[tex]\theta[/tex] = Angle = [tex]3.4\ ^{\circ}[/tex]

m = Mass of disk = 6.1 kg

Torsional constant is given by

[tex]J=\dfrac{\tau}{\theta}\\\Rightarrow J=\dfrac{FR}{\theta}\\\Rightarrow J=\dfrac{4.29\times 0.15}{3.4\times \dfrac{\pi}{180}}\\\Rightarrow J=10.84406\ Nm/rad[/tex]

The torsion constant is 10.84406 Nm/rad

Moment of inertia is given by

[tex]I=\dfrac{1}{2}mr^2\\\Rightarrow I=\dfrac{1}{2}6.1\times 0.15^2\\\Rightarrow I=0.068625\ kgm^2[/tex]

The moment of inertia is 0.068625 kgm²

Frequency is given by

[tex]f=\dfrac{1}{2\pi}\sqrt{\dfrac{J}{I}}\\\Rightarrow f=\dfrac{1}{2\pi}\sqrt{\dfrac{10.84406}{0.068625}}\\\Rightarrow f=2.00066\ rad/s[/tex]

The frequency is 2.00066 rad/s

Time period is given by

[tex]T=\dfrac{1}{f}\\\Rightarrow T=\dfrac{1}{2.00066}\\\Rightarrow T=0.49983\ s[/tex]

The time period is 0.49983 s