Exam

JEE Main

Year

2017

Date

9 April

Mode

Online

Subject

Physics

Chapter

Laws of Motion

JEE Main 2017 · 9 April · Online · Physics · Laws of Motion

A conical pendulum of length l makes an angle θ = 45 ° with respect...

A conical pendulum of length $l$ makes an angle $\theta = 45 °$ with respect to $Z -$axis and moves in a circle in the $XY$ plane. The radius of the circle is $0.4m and its center is vertically below$O$. The speed of the pendulum, in its circular path, will be - \left(Takeg = 10m{s}^{- 2}\right)$

Step-by-step solution

Tsin \theta = \dfrac{m{v}^{2}}{r}$<br /><br />Tcos \theta = mg$

$tan \theta = \dfrac{{v}^{2}}{rg}$

$\theta = {45}^{o}$

${v}^{2} = rg$

$v = \sqrt{rg} = \sqrt{0.4 \times 10}$

$v = 2m{s}^{- 1}$