A train has to negotiate a curve of radius $200\;m$ . By how much should the outer rails be raised with respect to the inner rails for a speed of $36\;km\;h^{-1}$. The distance between the rails is $ 1.5\;m$ Take $g=10 \;m /s^2$

Question

$\begin{array}{1 1} 7.5\; cm \\ 10\;cm \\ 12.5\;cm \\ 15 \;cm \end{array} $