question_answer

A motor cycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it

A) increases

B)                       decreases

C) remains the same           

D) fluctuates erratically

Correct Answer: A

Solution :

Reaction of normal force on the motor cyclist \[Mg\cos \theta -N=\frac{m{{v}^{2}}}{R}\] or            \[N=Mg\,\cos \theta -\frac{M{{v}^{2}}}{R}\] As the motor cyclist moves upward on the bridge,\[\theta \]decreases and therefore, N increases and becomes maximum at the highest point.