A thin uniform rod,pivoted at O, is rotating in the horizontal plane with constant angular speed ω, as shown in the figure. At time t = 0, a small insect starts from O and moves with constant speed v,

Question

A thin uniform rod,pivoted at O, is rotating in the horizontal plane with constant angular speed ω, as shown in the figure. At time t = 0, a small insect starts from O and moves with constant speed v,with respect to the rod towards other end. It reaches the end of the rod at t = T and stops.The angular speed of the system remains ω throughout. The magnitude of the torque $(|\vec{τ}|)$ about O,as a function of time is best represented by which plot?

TestHub · Accepted Answer

angular momentum J = Iw z = dJ dt = w dI Dt [ I = I rod + I insect = C + mr 2 ⇒ c + m ( vt ) 2 ] τ = ω dI dt = ω d dt C + mv 2 t 2 = m ω v 2 2 t So, the graph between τ and t is straight line.

Physics - Rotation Question with Solution | TestHub

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