Question

An express train is running between two stations with the uniform speed. If the diameter of each wheel of train is 42cm and each wheel makes 1200 revolution per minute. Find the speed of the train.

Answer 1

Diameter of each wheel =42cm
therefore radii=21cm

No. of revolution in 1 min=1200

Distance covered by the wheel in 1 revolution= 2$\pi$r
=2×$\frac{22}{7}$×21=132 cm


Distance covered by wheel in 1min=Distance covered by the wheel in 1200 revolutions= 132×1200= 158400 cm= 1584 m 

Speed of train=1584m/min =1584×$\frac{1}{100}$ km / $\frac{1}{60}$ hour =1584×60/1000 km/hr.

= ANS. 95.04 km/hr approx

HOPE THIS HELPS!!!

Answer 2

Answer:

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