An Express Train is Running Between Two Stations with a Uniform Speed. If the Diameter of Each Wheel of the Train is 42 Cm and Each Wheel Makes 1200 Revolutions per Minute, - Mathematics

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Sum

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

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Solution

radius of the wheel = `42/2` = 21 cm

Circumference of the wheel = 2π x 21 = 132 cm

Distance travelled in one minute
= 132 x 1200 
= 158400 cm
= 1.584 km

Hence the speed of the train
= `[1.584 "km"]/[1/60"hr"]`

= 95.04 km/hr.

  Is there an error in this question or solution?
Chapter 20: Area and Perimeter of Plane Figures - Exercise 20 (C) [Page 262]

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Selina Concise Mathematics Class 9 ICSE
Chapter 20 Area and Perimeter of Plane Figures
Exercise 20 (C) | Q 17 | Page 262

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