Question

a boy is cycling such taht wheels of the cycle are making 140 revolution per minute if the wheel is 60 cm calculate the speed in km per hour in which the body is cycling​

Answer 1

radius of well=60÷2=30cm

circumference of a wheel is 2πr=2×22÷7×30

=1320/7

distance in 140 revolution =1320/7×140=264/1000

it is given whell has take 140 revolution per min

distance in per min =distance in 140revolution

distance covered in 1hr=264/1000×60=15.84km

HENCE,the speed of cycling is 15.84km/hr.

Answer 2

5.8176 km/hr, speed= distance/time

time =140/60

distance=2πr.

on calculation you will get 1.616 and the convet it into km/hr multiplying 3.6.