The diameters of the front and rear wheels of a tractor are 80 cm and 2 m respectively. Find the number of revolutions that a rear wheel makes to cover the distance which the front wheel covers in 800 revolutions.


Given diameter of front wheel = d = 80 cm


so, Radius of front wheel = r = d/2 = 80/2 = 40 cm


Diameter of rear wheel = D = 2 m = 200 cm



Distance covered by wheel in 1 revolution = Circumference of wheel


Distance covered by front wheel = 2πr = 2π(40)


Distance covered by front wheel = 80π


Distance covered by front wheel in 800 revolutions = 80π×800


Distance covered by front wheel in 800 revolutions = 6400π eqn1


Similarly


Distance covered by rear wheel = 2πR = 2π(100)


Distance covered by rear wheel = 200π eqn2


Let the number of revolutions made by rear wheel to cover 6400π cm be “x”


(x)×200π = 6400π (from eqn1 and eqn2)



x = 64000/200


x = 320


Number of revolution made by rear wheel to cover the distance covered by front wheel in 800 revolutions is 320.


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