A scooter starting from rest moves wilth as constant acceleration for a time `/_ _1`, then with a constant velocity for the next `/_ _2` and finally with a constant deceleration for the next `/_ _3` to come to rest with resect to the scooter wilthout touching any other part. The force exerted by the seat on the man is
A. 500 N throughout the journey
B. Less than 500 N throughout the journey
C. More than 500 N throughout the journey
D. `gt` 500 N for time `Deltat_(1)` and `Deltat_(3)` and 500 N for `Deltat_(2)`
