• # question_answer The velocity- time graph of a car is a semi-circle as shown in the figure. Which of the following statement is correct? A)  The car must move in circular path.B)  Acceleration of the car is never zero.C)  The mean speed of the car is$\frac{\pi }{4}\,m/s.$D)  The car makes a turn once during its motion.

Total distance covered is given by the area under the curve. $\therefore$Total distance covered $=\frac{\pi \times {{1}^{2}}}{2}=\frac{\pi }{2}\,m.$ Total time taken = 2 sec. $\therefore$Total distance covered $=\frac{\pi \times {{1}^{2}}}{2}=\frac{\pi }{2}\,m.$ Total time taken = 2 sec. $\therefore$mean speed $=\frac{\pi /2}{2}=\frac{\pi }{4}m/s.$ Hence, the correction option is [c].