Question

In a conical pendulum, a string of length $120cm$ is fixed at rigid support and carries a mass of $150g$ at its free end. If the mass is revolved in a horizontal circle of radius $0.2m$ around a vertical axis, calculate tension in the string. $(g=9.8m/s^2)$.

Answer 1

R.E.F image

In vertical direction,

$Tsin\theta =mg\left(i\right)$

In horizontal plane,

$Tcos\theta =\frac{m{v}^2}{R}$ [centripetal for

From (i), $T=\frac{mg}{sin\theta }$ = $\frac{mgl}{\sqrt{l^2-R^2}}$

$T=\left(\frac{150}{1000}\right)\frac{\left(10\right)\times 120}{(120{)}^2-(20{)}^2}=1.52N$