A cyclist starts from the centre O of a circular track of radius r = 1 km, reaches the edge P of the track and then cycles along circumference and stops at point Q. if the total time take is 10 min, what is the average velocity of the cyclist?                                                  


Correct option is

6 km h–1



The displacement of the cyclist in moving from P to Q along the circumference = shortest distance between P and Q = straight line distance PQ in the direction from P to Q. The net displacement in moving from O to P and then from P to Q = resultant of vector displacement OP and PQ. From the triangle law of vector addition, the magnitude of the net displacement = OQ = 1 km. Now, the time take = 10 min  Therefore, average velocity is 1 km/ = 6 km h–1.



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