Question

A train is moving with a speed of 12 m/s on rails which are 1.5 m apart. To negotiate a curve radius of 400 m, the height by which the outer rail should be raised with respect to the inner rail is (Given, $g = 10 \, \text{m/s}^2$):

• A. 6.0 cm
• B. 5.4 cm
• C. 4.8 cm
• D. 4.2 cm

Answer 1

Answer: (B)

5.4 cm

Answer 2

For a train moving around a curve, the required banking angle θ is given by:

$\tan \theta = \frac{v^2}{Rg}$

where $v = 12 \, \text{m/s}$, $R = 400 \, \text{m}$, and $g = 10 \, \text{m/s}^2$.

Substitute the values:

$\tan \theta = \frac{12^2}{10 \times 400} = \frac{144}{4000} = \frac{h}{1.5}$

where $h$ is the height by which the outer rail should be raised over the inner rail, and the distance between the rails is 1.5 m.

Solving for $h$:

$h = \frac{144 \times 1.5}{4000} = 5.4 \, \text{cm}$

Thus, the required height is 5.4 cm.