Disk acceleration physics homework

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monkey9988
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Homework Statement



A force of 2.2N acts tangentially to the rim of a solid 52kg disk, with a radius of 32cm. How long does it take to accelerate the disk, rotating about an axis though it's center and perpendicular to it's plane, from rest to 210 rev/min?

Homework Equations


Idisk=.5mr^2
T=I (weird fish symbol)
fish symbol = Wf - Wi
t


The Attempt at a Solution


i don't know how to find the weird fish symbol.. one because i don't know what it stands for and two. i need that inorder to find time..

HELP PLEASE!?
 
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monkey9988 said:

Homework Statement



A force of 2.2N acts tangentially to the rim of a solid 52kg disk, with a radius of 32cm. How long does it take to accelerate the disk, rotating about an axis though it's center and perpendicular to it's plane, from rest to 210 rev/min?

Homework Equations


Idisk=.5mr^2
T=I (weird fish symbol)
fish symbol = Wf - Wi
t

The Attempt at a Solution


i don't know how to find the weird fish symbol.. one because i don't know what it stands for and two. i need that inorder to find time..

HELP PLEASE!?
Welcome to PF.

The weird fish symbol is the greek letter alpha: [itex]\alpha[/itex] which means angular acceleration and has units of radians/time^2. The relationship between acceleration (distance/time^2) and [itex]\alpha[/itex] for a point rotating about a centre of rotation located at a distance r away is: [itex]\alpha = a/r[/itex].

The relationship between torque and angular acceleration for a rigid object is:

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

In order to answer this question, you will have to understand what that equation means.

AM