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mstram
New Member
11 Posts
Toronto, Ontario
Canada
(None)

Posted  07/19/2015 : 4:18 AM
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I've been reading about torque, angular momentum, angular acceleration, and I think I understand the basics. Or do I ? :)
Given :
A (hypothetical) wheel with a m.o.i. of 1 lb*ft^2
Radius of wheel = 1.9099 inches, therefore circumference of wheel = 1 foot
The wheel is at rest, (zero rotation).
A torque of 1 ft/lb is applied for 1 second
Is the result a rotation of 1 r.p.s. (60 r.p.m.) ?
Mike

Edited by  mstram on 07/19/2015 6:48 AM 

DataDan
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585 Posts
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Central Coast, CA
USA
Yamaha
FJR1300

Posted  07/19/2015 : 9:08 AM

Moment of inertia is in units of mass * distance^2.
Torque is in units of force * distance. (And note that this should be expressed as lbft, not lb/ft.)
It might be easier to restate in metric units (e.g., kilos and newtons) to avoid this confusion.
Two ways to approach the problem:
1) Torque applied through angle of rotation = work = kinetic energy, from which rotation speed can be calculated.
2) Torque / MoI = angular acceleration, which can be multiplied by time to get rotational speed. 


mstram
New Member
11 Posts
Toronto, Ontario
Canada
(None)

Posted  08/01/2015 : 1:11 PM

quote: Originally posted by DataDan
Torque is in units of force * distance. (And note that this should be expressed as lbft, not lb/ft.)
After much (more) reading / searching it seems to me they should have named the torque unit lb32p2ft (poundforce) 



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