Question

A 55 kg person is sitting in a car that hits a concrete floor.The car was moving at 30 m/s and came to a halt in 0.35s.What is the average force that the seatbelt exerts on the person.

Answer 1

-4714.28N

Step-by-step explanation:

Given

• Mass of person, m= 55 kg
• Car speed initially ,u =30
  `(m)/(sec)`
• 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

⇒
`F* t= mv-mu\\F *0.35= 55* (0-30)\\F* 0.35= -1650\\F= -4714.28 N`

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