Question

A scooter starting from rest moves with a constant acceleration for a time $\Delta$ $t_1$, then with a constant velocity for the next $\Delta$ $t_2$, and finally with a constant deceleration. A person of mass 50 kg on the scooter, behind the driver manages to stay at rest with respect to the scooter without touching any other part. The force exerted by the seat on the man is

Take g=10m/ $s^2$

• A. 500 N throughout the journey
• B. less than 500 N throughout the journey
• C. more than 500 N throughout the journey
• D. > 500 N for time $△$ $t_1$ and $△$ $t_3$, and 500 N for $△$ $t_2$,

Answer 1

The correct option is D

> 500 N for time $△$ $t_1$ and $△$ $t_3$, and 500 N for $△$ $t_2$,

So when scooter is accelerating the man is also accelerating along with it so friction from the scooter's seat on man is making him move forward.

Also there is a Normal force

N = mg = 500 N

So Net force while accelerating will be $\sqrt{{\left(500\right)}^2+{\left(f_r\right)}^2}$ > 500

Same is true about decelerating

So while accelerating or decelerating the force on man by scooter is more than 500N. When the scooter is going with constant velocity, the man is also going with constant velocity. So 0 acceleration in horizontal direction so no net force in horizontal direction so no friction.

Only Normal N = mg = 500