Question

the radius of a wheel of a car is 0.6 metre it makes 140 revolution in a minutes find the speed of the car in kilometre per hour​

Answer 1

Given,

r= 0.6

So, distance covered in one rotation is 2πr

= 2*3.14*21

= 131.88cm

Rpm =600

So

Distance covered in a minute

= 600*131.88

= 791.28m/min

Convert this to kmph

=(791.28/1000)/(1/60)

=47.5 kmph