Question

A string is wrapped around a cylinder of mass $M$ and radius $R$. The string is pulled vertically upwards to prevent the centre of mass from falling as the cylinder unwinds the string, The tension in the string is

• A. $\frac{2Mg}{3}$
• B. $\frac{Mg}{2}$
• C. $Mg$
• D. $\frac{Mg}{6}$

Answer 1

Answer: (C)

$Mg$

External force on the cylinder is Tension $T$ and the gravitational force $mg$.

As the center of cylinder should not move, the linear force must balance $\therefore T=mg$