NEET-XII-Physics
10: Rotational Mechanics
- #12Equal torques act on the disc A and B of the previous problem, initially both being at rest. At a later instant, the linear speeds of a point on the rim of A and another point on the rim of B are
νAand
νBrespectively. We have
(a)
νA > νB
(b)
νA = νB
(c)
νA < νB
(d) the relation depends on the actual magnitude of the torques.digAnsr: aAns : (a) `` {\nu }_{A}>{\nu }_{B}``
`` \tau =I\alpha \left(\,\mathrm{\,magnitude\,}\right)``
`` ``
For equal torque, we have:
`` {I}_{A}{\alpha }_{A}={I}_{B}{\alpha }_{B}``
IA < IB
⇒ `` {\alpha }_{A}>{\alpha }_{B}`` ...(i)
Now, `` \omega =\alpha t``
Or, `` \frac{v}{r}=\alpha t``
`` {\nu }_{A}>{\nu }_{B}`` (using (i))
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