Most of us know intuitively that in a head-on collision between
a large dump truck and a subcompact car, you are better off being
in the truck than in the car. Why is this? Many people imagine that
the collision force exerted on the car is much greater than that
exerted on the truck. To substantiate this view, they point out
that the car is crushed, whereas the truck is only dented. This
idea of unequal forces, of course, is false; Newton's third law
tells us that both objects are acted upon by forces of the same
magnitude. The truck suffers less damage because it is made of
stronger metal. But what about the two drivers? Do they experience
the same forces? To answer this question, suppose that each vehicle
is initially moving at 8.10 m/s and that they undergo a perfectly
inelastic head-on collision. Each driver has mass 78.0 kg.
Including the masses of the drivers, the total masses of the
vehicles are 800 kg for the car and 4,000 kg for the truck. If the
collision time is 0.140 s, what force does the seat belt exert on
each driver? (Enter the magnitude of the force.)