Moment of Inertia - Swinging arms

1. Apr 22, 2013

elemis

My workings are below :

Following the calculation of w I use v=wr where r= 3 and calculate the tangential velocity.

It's then easy to see that a speed of 340 (Mach 1) will be attained in 128 s

Is this correct ?

2. Apr 23, 2013

haruspex

In your handwritten working, you've written omega instead of omega-dot, but otherwise it all looks correct.

3. Apr 23, 2013

elemis

I dont understand you. Torque = Iw , correct ?

4. Apr 23, 2013

hms.tech

No, it is

τ = Iα

where α is the angular acceleration

Last edited: Apr 23, 2013
5. Apr 23, 2013

haruspex

... and although the OP says "I use v=wr ", what has actually been used is a = αr.