Question

A circular disc is rotating with constant $\omega =2$ rad/sec, about an axis passing through its centre. Two objects are kept at a distance of ${}^{\prime }{r}_1=2c{m}^{\prime }$ and ${}^{\prime }{r}_2=1c{m}^{\prime }$ from the centre. The ratio of their linear speeds is.

• A. 2:1
• B. 4:1
• C. 1:1
• D. 2:4

Answer 1

The correct option is A 2:1

$v=r\omega$

$v_1=r_1\omega =2\times 2=\frac{4cm}{sec}$

$v_2=r_2\omega =1\times 2=\frac{2cm}{sec}$

$\frac{v_1}{v_2}=\frac{4}{2}=\frac{2}{1}$