A flywheel with an axle 1.0cm in diameter is mounted in frictionless bearings and set in motion by applying a steady tension of 2N to a thin thread wound tightly round the axle. The moment of inertia of the system about its axis of rotation is 5.0 x 10^-4 kgm^-2. Calculate (a) the angular acceleration of the flywheel when 1 m of thread has been pulled off the axle. (b) the constant retarding couple which must then be applied to bring the flywheel to rest in one complete turn, the tension in the thread having been completely removed.

Answer 1

Start withe the equation
Torque = (Moment of inertia)(angular acceleration)
which is sometimes written in textbooks as
T = I*alpha
(a) The angular acceleration will not depend upon how much thread has been pulled, but the angular velocity achieved (Wmax)will depend upon that length, or how long one has been pulling.
(b) Use the same equation to compute the retarding torque, after first calculating how large the angular deceleration rate (alpha') must be to stop the turning within one revolution.
To do this, require that (Wmax/2)*T = 2 pi radians; solve for T, and get the required decleration rate from alpha' = Wmax/T

Answer 2

Jade Craven August 11, 2011 am31 8:48 Totally Transparency is overrated. I'm woikrng on a post on how some people thrive as an employee rather than an entrepreneur, so a little bit of that slipped out at the end of the post. I'm really interested in hearing about the hard slog and challenges people went through as part of a larger journey but that just reflects my latest reading interests, which is focused on startups.The crux of it was, business takes more effort then being an employee. Don't get fooled by the lifestyle claims. If building your own business is proving too stressful, take a step back to part time employment and pursue your creative entrepreneurial projects with a financial buffer. There's no shame and it can lead to greater personal success.I'm going to be talking less about myself here and more about theories, anyway. I've deleted the overly personal stuff.Anyhoozle flywheels FTW.

Answer 3

Need help for the above questions or any solved examples

Answer 4

first u have to find Torque = (Moment of inertia)(angular acceleration)
which is sometimes written in textbooks as
T = I*alpha
then find Theta (θ)=2pie
then use omega(w)=torque*(θ)
then we khow (w)=froce*distance and find torque