Chapter 7 - Circular Motion and Gravitation - Learning Path Questions and Exercises - Exercises - Page 262: 44

a). $8rad/s^{2}$ b). $16$

a). Angular acceleration =$\frac{\Delta\omega}{\Delta t}=\frac{40}{5}=8 rad/s^{2}$ b). $\omega^{2}=\omega_{0}^{2}+2a\Delta\theta$ Thus, $\Delta\theta=\frac{40^{2}}{2\times8}=100rad$ No of revolutions $=\frac{100}{2pi}=16$