Question

a wheel of the bus is 90cm diameter make 210 revolution in per minute find the speed of the bus in kilometre per hour​

Answer 1

the DIAMETER IS 90cm so

radius=45 cm

circumference of the circle=2(pie) r

=2×22×45

7

=2×22×45

7 100000

(Converting in kilometers)

Revolution/minute is 210,

=2×22×45× 210×60

7 100000

(×60 because it is per hour)

(substitute and you will get)

=35.64