Q. A motor cycle is moving with the speed of 47.52 km/hr and the radius of the wheel of the motorcycle is 21 cms. Calculate the approximate no of revolutions made by the wheel in one minute.
Option
A) 400 rpm
B) 500 rpm
C) 600 rpm
D) 700 rpm

• Given Speed = 47.52 km/h = 47.52 * 1000/60 m/s
  = 792 metre/minute
  the radius of the wheel of the motorcycle = 21 cm
  circumference of the wheels = 2*22/7*21 = 132cm = 1.32 m
  
  Number of revolutions made by the wheel in one minute
  = Speed (in metre/minute)/circumference(in m)
  = 792/1.32 = 600
  So no of revolutions made by the wheel in one minute will be 600
  
  
  
• 11 years agoHelpfull: Yes(38) No(0)
• 1 rev=2*(22/7)*21 cm=132 cm
  speed=47.52 km/hr=79200 cm/sec
  therefore no of revolution in in 1 min=79200/132=600 ans
  ans: c
• 11 years agoHelpfull: Yes(5) No(0)
• Distance covered in 1 hr(60 min)=47.52km
  So, distance covered in 1 min= (47.52/60) =0.792km=0.792*1000*100=79200cm
  
  Now ,Distance coverd in 1 revolution of wheel=2*pi*r=2*(22/7)*21=132 cm
  
  So total no of revolution to cover 79200 cm= 79200/132=600 rpm
• 10 years agoHelpfull: Yes(2) No(0)
• ans:600rpm
• 11 years agoHelpfull: Yes(1) No(0)
• shalu singh don't give the answer directly, readers are not as clever as u
  
• 11 years agoHelpfull: Yes(1) No(0)
• Anyone explain me in a simple method pls !!!
• 9 years agoHelpfull: Yes(0) No(0)