# A bicycle wheel, diameter 56 cm, is making 45 revolutions in every 10 seconds. At what speed, in kilometer per hour. Is the bicycle travelling?

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by tkm

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by tkm

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radius=diameter/2=56/2=28cm

now, we are gonna find Periphery

Periphery=2πr

=(2)*(3.14)*(28)

=176 cms per rotation

so now it goes for 176 cms per rotation. and we are told about 45, so

according to the speed-distance/time, we must find the distance first.

Now it goes on 45 revolutions per 10 seconds that means it goes on 45*6 revolutions per 10*6 seconds, that means 270 revolutions per minute. and similarly to find the hour rate it goes on 270*60 rotation per hour [1 min*60]

that means it's going on 16200 revolutions per hour. Now multiply the 16200 with the Periphery.

=16200*176

=2851200 centimeters per hour.

Now convert the centimeters into kilometers, that means the answer is.... 28.512 kilometers per hour.

so your answer is

By the way, nice question. ^_^

Diameter = 56 cm

radius = D / 2 =

no. of revolutions (n) = 45

time ( t) = 10 sec

revolutions per second = 45 / 10 =

Distance(D) covered per second = Perimeter of the wheel

Speed = Distance / Time

S = 2πr × 4.5

⇒ S = 176 cm × 4.5 per sec

⇒ S = 1.76 metre × 4.5 per sec

⇒ S =

I hope my answer is correct!

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Thank you!