• # question_answer When a ceiling fan is switched off, its angular velocity falls to half while it makes 36 rotations. how many rotation will it make before coming to rest? A)  24                                B)  36 C)  18                                D)  12

Angular motion $={{\omega }^{2}}=\omega _{0}^{2}-2\alpha \theta$ (here, ($\omega =0$) $\therefore \,\,0=\,{{\left( \frac{{{\omega }_{0}}}{2} \right)}^{2}}-2\times \,\frac{\omega _{0}^{2}.\,\theta }{16\times 12\pi }$ Or $\theta =24\,\pi \,or\,\,\theta =12\times 2\pi$ But $2\pi =1$ cycle, So, $\theta =12$ cycle