Some automobiles have air bags installed on their dashboards as a safety measure. The impact of a collision causes the bag to inflate, and it then cushions a passenger's head when he is thrown forward in the car. Suppose that such a bag could lengthen the collision time between one's head and the dashboard by a factor of 10. What effect would this have on the force exerted on the head?
A) The force would be reduced by a factor of about 100.
B) The force would be reduced by a factor of about 1000.
C) The force would be reduced by a factor of about 10.
D) The force would be reduced by a factor of about 3.
E) The force would not be reduced, but the energy transferred to the head would be, thereby minimizing the damage done.

Question

Quizplus · Accepted Answer

According to Newton's second law and the impulse-momentum theorem, the force experienced by an object is inversely proportional to the time over which the force is applied. Therefore, if the collision time is increased by a factor of 10, the force exerted on the head would be reduced by the same factor.

Some Automobiles Have Air Bags Installed on Their Dashboards as a Safety