Question

in an emergency stop to avoid an accident, a shoulder strap seat belt holds a 60 kg passenger firmly in place. if the car were initially traveling at 90 km/h and came to a stop in 5.5 s along a straight, level road, what was the average force applied to the passenger by the seat belt?

Answer 1

272.727N

Step-by-step explanation:

Force is equal to the product of mass and acceleration. We know the mass of the person (60kg), so we just need to find how much they are decelerating when coming to a stop.

We do this using the motion equation v=u+at, where v is the final velocity, u is initial velocity, a is acceleration, and t is time. Noting 90km/hr=25m/s, we get:

0=25+5.5a

a=-4.5454545m/s^2

Force = mass * acceleration = 60 * 4.545 = 272.727N