Loading [MathJax]/jax/output/HTML-CSS/jax.js


1)

A disc has mass 'M' and radius  'R'. How much tangential force should be applied to the rim of the disc, so as to rotate with angular velocity 'ω ' in time 't'?


A) MRω4t

B) MRω2t

C) MRωt

D) MRωt

Answer:

Option B

Explanation:

 Given, mass of disc= M

 Radius of disc= R

 we know that,

   τ=lα

 But , τ=F×R

    l=MR22

 and   α=ωt

 therefore  , F x R= MR22×ωt

 F= MRω2t