Question

A solid cylinder length is suspended symmetrically through two massless strings, as shown in the figure. The distance from the initial rest position, the cylinder should be unbinding the strings to achieve a speed of 4 m/s, is ______ cm. (Take g = 10 m/s2).

Fig.

Answer 1

The correct answer is 120
$α = \frac{(mg)(r)}{\frac{3}{2}mr^2} = \frac{2g}{3r}$
$⇒ a = \frac{2g}{3}$
$⇒ v^2 = 2as$
$16 = \frac{40}{3}×s$
⇒ s = 0.3×4
= 120cm