Home » Aptitude » Speed, Time and Distance » Question
  1. A car is moving with the speed of 47.52km/hr and the radius of the wheel of car is 21 cm. Calculate the approximate number of revolutions made by the wheel in one minute.
    1. 250 rpm
    2. 200 rpm
    3. 600 rpm
    4. 300 rpm
Correct Option: C

Speed in cm/minute = (Speed in km/hr x 1000 x100 )/60
= 47.52x(50/3)
=79200 cm/min

And Circumference of circle = 2πr
=2 x ( 22 / 7 ) x 21
=132

No. of revolutions = ( Speed in cm/minute ) / circumference of circle in cm
=79200 / 132
=600 rpm



Your comments will be displayed only after manual approval.