How many rotations per minute must a wheel of diameter 1.5m make to achive a speed of 45kmph?(Approx pi=3)

• distance to be covered in 1 min.=(45*1000/60)m =750 m
  circumference of wheel = 2*3*1.5/2 =4.50
  number of revolutions per min. =(750/4.50) =166.67
• 8 years agoHelpfull: Yes(8) No(2)
• 1666.66 rpm
  
• 8 years agoHelpfull: Yes(1) No(0)
• distance covered in 1 minute = 45*1000/60
  this distance is equal to distance covered in n rotations
  distance covered in 1 rotation=circumference
  pi*d*n=45*1000/60
  n=167
• 7 years agoHelpfull: Yes(1) No(0)
• distance to be covered in 1 min.=(45*1000/60)m =750 m
  circumference of wheel = 2*3*1.5/2 =4.50
  number of revolutions per min. =(750/4.50) =166.67
• 8 years agoHelpfull: Yes(0) No(0)
• 45 kmph = 45x1000/60 m/min = 750m/min( U). U= pi DN or N=U/pi D = 750/3x1.5 = 166.66 rpm
• 7 years agoHelpfull: Yes(0) No(0)
• =1.5M SPEED =45KMPH Pi(Given)=3
  R=1.5/2m=0.75m
  
  circumference =
  2xpixR
  So,
  
  2x3x0.75 =6x0.75=4.5rev/60 =0.075m/min
  
  c= 0.075
  
  for 45mph speed 45x0.075x100=3375rev/min
  
  rotations per min =3375/60
  
  approx 55 rev/min
  
  No of rotations per min = 55 rev/min
  
  No of rotations need to cover d= 55/4.5=12.22rotations
  
  Therefore in 45mph whell need to take 12.22 rotations /min to cover 45mph
• 7 years agoHelpfull: Yes(0) No(3)
• so here to solve this question, we have given the required speed which is 45km/hr.
  
  so, distance covered by wheel in one minute= (45*1000*100)/60 cm= 75000 cm.
  
  now we have to calculate circumference of the wheel= 2*pi*r = 2*3*75 cm= 450 cm
  
  so number of rotations per minute= 75000/450 = 500/3 = 166.67 rotations per minute.
• 1 year agoHelpfull: Yes(0) No(0)
• 45/1.5*3=10
• 1 year agoHelpfull: Yes(0) No(0)