Medium INTEGER +4 / -1 PYQ · JEE Mains 2020

A body of mass m = 10 kg is attached to one end of a wire of length 0.3 m. The maximum angular speed (in rad s–1) with which it can be rotated about its other end in space station is :
(Breaking stress of wire = 4.8 × 107 Nm–2 and
area of cross-section of the wire = 10–2 cm2) is:

Answer (integer) 4

Solution

T = m${\omega ^2}l$ <br><br>Breaking stress = $\sigma$ = ${{m{\omega ^2}l} \over A}$ <br><br>$\Rightarrow$ ${\omega ^2}$ = $${{4.8 \times {{10}^7} \times \left( {{{10}^{ - 2}} \times {{10}^{ - 4}}} \right)} \over {10 \times 0.3}}$$ = 16 <br><br>$\Rightarrow$ $\omega$ = 4

About this question

Subject: Physics · Chapter: Rotational Motion · Topic: Centre of Mass

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