Saving Lives Through Seat Belts & Air Bags

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In summary, seat belts and air bags are important safety features in cars as they reduce the forces exerted on the driver and passengers during collisions. A car's front end is designed to crumple upon impact, allowing the passenger compartment to decelerate over a longer distance. An occupant wearing a seat belt and with an air bag deployed will decelerate with the car, compared to an unrestrained occupant who will keep moving forward until hitting the dashboard or windshield. In the given scenario, a 60 kg person in a head-on collision with a car speed of 11m/s will experience a net force of 3630N if restrained by a seat belt and air bag, and a force of -3630N if
  • #1
aligass2004
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Homework Statement


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 even of an impact, the passenger compartment decelerates over a distance of about 1m 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 until hitting the dashboard or windshield. These are unyielding surfaces, and the unfortunate occupant then decelerates over a distance of only about 5mm. a.) A 60 kg person is in a head-on collision. The car's speed at impact is 11m/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 forces compare to the person's weight? (They want to know F(a)/W = ? and F(b)/W = ?)


Homework Equations


F=ma


The Attempt at a Solution


I don't even know where to begin with this problem. I sat and read it a couple of times, and just had no idea where to begin.
 
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  • #2
The main part of the problem is to find the acceleration... for the first case initial velocity is 11m/s... he comes to a stop over 1m... what is the accleration?

second case again initial velocity is 11m/s... he comes to a stop over 5mm... what is the accleeration?

force is just mass times acceleration.
 
  • #3
Having problems finding the acceleration. I got -60.5.
 
  • #4
aligass2004 said:
Having problems finding the acceleration. I got -60.5.

Yes, that's correct. So what's the force?
 
  • #5
The force would be 3630N? I put that, and it said it was wrong.
 
  • #6
aligass2004 said:
The force would be 3630N? I put that, and it said it was wrong.

Hmmm... maybe -3630N ? I'm not sure...
 
  • #7
Nope, I tried that too.
 
  • #8
aligass2004 said:
Nope, I tried that too.

I don't understand why it isn't accepting the answer... Is the system sensitive about significant figures?
 
  • #9
I don't think it is. We use WebAssign.
 

FAQ: Saving Lives Through Seat Belts & Air Bags

1. How do seat belts and air bags save lives?

Seat belts and air bags work together to protect passengers during a car accident. The seat belt keeps the occupant from being thrown forward, while the air bag cushions the impact of the collision. This reduces the risk of serious injuries or death by preventing the occupants from hitting the hard surfaces inside the car, such as the dashboard or windshield.

2. Do all cars come with seat belts and air bags?

Yes, it is a legal requirement for all passenger vehicles to have seat belts and air bags installed. Additionally, most modern cars also have advanced air bag systems that deploy based on the severity of the crash, the position of the occupant, and other factors. However, it is important to always check and make sure that your car's seat belts and air bags are in proper working condition.

3. Are there any risks associated with using seat belts and air bags?

While seat belts and air bags are designed to keep occupants safe, there are some potential risks associated with their use. For example, air bags can cause injuries if they deploy with too much force or if the occupant is positioned too close to the air bag. Seat belts can also cause injuries such as bruises or broken ribs if they are not worn properly. However, the benefits of using seat belts and air bags far outweigh the risks.

4. Can seat belts and air bags prevent all injuries in a car accident?

No, seat belts and air bags cannot prevent all injuries in a car accident. They are designed to reduce the severity of injuries, but they cannot eliminate the risk entirely. In some cases, the force of the impact or the type of collision may be too great for seat belts and air bags to fully protect the occupants. It is important to always follow traffic laws and drive safely to minimize the risk of accidents.

5. Are there any other safety measures that can be used in addition to seat belts and air bags?

Yes, there are other safety measures that can be used in conjunction with seat belts and air bags to further enhance passenger safety. These include child safety seats for young children, properly adjusting the headrests in the car, and avoiding distractions while driving. It is important to use all available safety measures to reduce the risk of injuries in a car accident.

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