A circular disc of mass 2 ,kg and radius 10 ,cm rolls without slipping with a speed 2 ,m / s . total

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6.System of Particles and Rotational Motion

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A circular disc of mass $2 \,kg$ and radius $10 \,cm$ rolls without slipping with a speed $2 \,m / s$. The total kinetic energy of disc is .......... $J$

A

$10$

B

$6$

C

$2$

D

$4$

Solution

(b)

$k=\frac{1}{2} m v^2+\frac{1}{2} l \omega^2$

$=\frac{1}{2} m v^2+\frac{1}{2} \frac{m l^2}{2} \cdot \frac{v^2}{l^2}$

$=\frac{3}{4}(2)(2)^2$

$=6 \,J$

Standard 11

Physics

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