二、The figure below shows an accident. Car A slid into the rear of car B,which was stopped at a red light along a road headed down a hill. Theslope of the hill is . The cars were separated by distancem when the driver of car A put the car into a slide (it lackedany automatic anti-brake-lock system), and that the speed of car A at theonset of braking was m/s. With what speed did car A hit carB if the coefficient of kinetic friction was 0.60? 【Hint】: 1. the magnitude of the free-fall acceleration $g = 9.8 \, \mathrm{m/s}^2$ . 2. $\sin 12^{\circ} \approx 0.20$ ; $\cos 12^{\circ} \approx 0.98$ . 3. $v = v_{0} + at$ . 4. $S = v_{0}t + \frac{1}{2} at^{2}$ . 5. $v^{2} = v_{0}^{2} + 2aS$ .