No of course, the brake only applies to the friction surface which it is applied to.
With that in mind then, the retarding force is 2 500 N and the brake torque must only be applicable to 0.30-0.12 = 0.18m
The time i now get is 54.945 sec
That was pretty careless of me, i took the first answer google gave me and took that as an absolute.
So, now using a density of 7850 kg / m3 and plugging it in, gives me 18.315 sec
- would you say this is a hit or a miss value?
My mistake. Following the below procedure i get 835kg not 169kg
This is what i assumed you can do to calculate mass.
mass = density x area x width
= 8050 x (pi x 0.45^2) x 0.163
=835 kg
(mass seems a little too big for the actual size of this flywheel though)
Anyways, calculating the time...
Okay, following the lead given by SteamKing (thank you for the point out).
The mass calculation went as follows:
mass = density x area x width
= 169 kg
The inertia of the flywheel is then given by:
I =(1/2)mr^2
= 17.111 kg.m^2
Then i was thinking of using Newtons second law of F = ma but...
Homework Statement
Hey y'all. Heres the problem:
The flywheel to the right is spinning at 300 radians per second in a counter clockwise direction. The
brake (to the left) is applied with a force F of 5kN.
How long will it take the flywheel to stop rotating?
Assume:
The flywheel is made of...