Answer:
-4714.28N
Step-by-step explanation:
Given
- Mass of person, m= 55 kg
- Car speed initially ,u =30

- Car speed finally, v=0(car comes to a halt)
- Duration for the car to come halt,t=0.35 sec
This question is based on the concept of Impulse
Impulse is the force acting in a time interval(usually very short)
it is equal to force multiplied with time and also equal to change in momentum of body
⇒

Therefore the seat belt exerts a force of -4718.28N on the person
The negative sign signifies that seat belt exerts force in opposite direction of Force