Question

A train has to negotiate a curve of radius $400m$. By how much height should the outer rail be raised with respect to inner rail for a speed of $48km/hr$? The distance between the rails is $1m$.

• A. $9cm$
• B. $4.5cm$
• C. $3cm$
• D. $7cm$

Answer 1

The correct option is B $4.5cm$

Let the width of the path be $b$

and $h$ its height. Let $v$ be the safe velocity

$\tan \theta =\frac{v^2}{rg}=\frac{h}{b}\Rightarrow h=\frac{v^{2}b}{rg}=\frac{{(48\times \frac{1000}{3600})}^2\times 1}{400\times 9.8}=0.0045m=4.54cm$