The wheel of a motor cycle is of radius 35 cm. How many revolutions per minute must the wheel make, so as to keep a speed of 66 km/h?


Radius of wheel = r = 35 cm


1 revolution of the wheel = Circumference of the wheel


= 2πr


= 2 × (22/7) × 35


= 220 cm


But Speed of the wheel = 66 km/hr


= cm/min


= 110000 cm/min


Number of revolutions in 1 min = 110000/220 = 500


Hence, required number of revolutions per minute is 500.


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