question_answer

A motor cycle is going on an over bridge 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.