College Physics: A Strategic Approach (3rd Edition)
3rd Edition
ISBN: 9780321879721
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
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Chapter 5, Problem 55GP
Seat belts and air bags save lives by reducing the forces exerted on the driver and passengers in an automobile collision. Cars are designed with a “crumple zone” in the front of the car. In the event of an impact, the passenger compartment decelerates over a distance of about 1 m as the front of the car crumples. An occupant restrained by seat belts and air bags decelerates with the car. By contrast, an unrestrained occupant keeps moving forward with no loss of speed (Newton’s first law!) until hitting the dashboard or windshield, as we saw in Figure 4.2. These are unyielding surfaces, and the unfortunate occupant then decelerates over a distance of only about 5 mm.
a. A 60 kg person is in a head-on collision. The car’s speed at impact is 15 m/s. Estimate the net force on the person if he or she is wearing a seat belt and if the air bag deploys.
b. Estimate the net force that ultimately stops the person if he or she is not restrained by a seat belt or air bag.
c. How do these two forces compare to the person’s weight?
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Chapter 5 Solutions
College Physics: A Strategic Approach (3rd Edition)
Ch. 5 - An object is subject to two forces that do not...Ch. 5 - Are the objects described here in static...Ch. 5 - What forces are acting on you right now? What net...Ch. 5 - Decide whether each of the following is true or...Ch. 5 - An astronaut takes his bathroom scale to the moon...Ch. 5 - A light block of mass m and a heavy block of mass...Ch. 5 - a. Can the normal force on an object be directed...Ch. 5 - A ball is thrown straight up. Taking the drag...Ch. 5 - You are going sledding with your friends, sliding...Ch. 5 - Suppose you are holding a box in front of you and...
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