Question

A motorcyclist is going on an over-bridge of radius, $R$. The driver is riding with a constant speed. As the motor cycle is ascending on the over-bridge, the normal force on it :

• A. increases
• B. decreases
• C. remains unchanged
• D. fluctuates

Answer 1

The correct option is A increases

From figure, reaction of normal force on the motor cyclist:
$mgcos\theta -R=\frac{m{v}^2}{r}R=mg\cos \theta -\frac{m{v}^2}{r}$
As motorcycle ascend on the over-bridge, angle of inclination of motorcycle with vertical decreases and becomes zero at at the highest point, so 'cos' goes on increasing and becomes 1 at highest point value of $R$ is continuously increasing while ascending.