The traffic police has installed Over Speed Violation Detection (OSVD) system at various locations in a city. These cameras can capture a speeding vehicle from a distance of $300\text{ m}$ and even function in the dark. A camera is installed on a pole at the height of $5\text{ m}$. It detects a car travelling away from the pole at the speed of $20\text{ m/s}$. At any point, $x\text{ m}$ away from the base of the pole, the angle of elevation of the speed camera from the car C is $\theta$. On the basis of the above information, answer the following questions : (i) Express $\theta$ in terms of height of the camera installed on the pole and $x$. (ii) Find $\frac{\mathrm{d}\theta}{\mathrm{d}x}$. (iii) (a) Find the rate of change of angle of elevation with respect to time at an instant when the car is $50\text{ m}$ away from the pole. OR (iii) (b) If the rate of change of angle of elevation with respect to time of another car at a distance of $50\text{ m}$ from the base of the pole is $\frac{3}{101}\text{ rad/s}$, then find the speed of the car.