Q6 of 37 Page 13

A car has wheels which are 80 cm in diameter. How many complete revolutions does each wheel make in 10 minutes when the car is moving at a speed of 80 km per hour?


Diameter of a car wheel = 80cm


∴ radius =


Distance covered in 1 revolution = Circumference of wheel


= 2πr


= 2 × π × 40


= 80π cm


Now, we find total distance covered


We know that,



Here, Speed = 80 km/hr


Time = 10 minutes



Putting a value in the formula, we get




⇒ Distance = 13.33 km


= 13.33 × 1000 m


= 1333.3 m


= 1333.3 × 100 cm


= 1333333.3 cm


Now,





= 5303.02


= 5303 (approx.)


Hence, number of revolutions = 5303


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