How much magnetic power is needed to stop a slow car.

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Discussion Overview

The discussion centers on the amount of magnetic force required to stop a car traveling at 15 mph, weighing 5071 lbs, and the specifications for a magnet or system capable of achieving this. Participants explore theoretical and practical aspects of using magnetic forces for braking, including the dimensions and power requirements of such a system.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about the magnetic force needed to stop the car and the dimensions of the required magnet.
  • Another participant suggests using magnetic calipers on a standard rotor but expresses uncertainty about power requirements.
  • Some participants request more specific examples of power requirements for the proposed system.
  • Concerns are raised about the feasibility of using magnetism for this application, noting that magnetism acts over short distances and that an electromagnet would be necessary.
  • It is mentioned that the required magnet might be heavier than the car itself and that the car's engine may not be able to power such a system.
  • A participant references the use of eddy brake retarders as a potential solution, discussing their specifications and costs.
  • Another participant suggests using powerful electromagnets instead of hydraulic systems for braking.

Areas of Agreement / Disagreement

Participants express varying opinions on the feasibility of using magnetic forces to stop a car, with some suggesting alternative braking systems. There is no consensus on the practicality or specifications of the proposed magnetic system.

Contextual Notes

Participants note limitations in the original question, including a lack of specifications and the complexity of power requirements for the proposed magnetic system. The discussion reflects uncertainty regarding the technical aspects and feasibility of the ideas presented.

Who May Find This Useful

This discussion may be of interest to those exploring innovative braking systems, magnetic applications in automotive engineering, or the theoretical limits of magnetism in practical scenarios.

Lancer2death
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Hello everyone, I need to figure out how much magnetic force is required to stop a car going 15 mph, weighing 5071 lbs, at an angular velocity of 1rad/s, with a force of 30,848 Newton’s, and accelerating at13.41 m/s^2. In addition, what would the size(dimensions) of this magnet have to be? Meaning, what magnet or contraption would have enough magnetic force to stop this car with characteristics I mentioned above.
 
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Lancer2death said:
Hello everyone, I need to figure out how much magnetic force is required to stop a car going 15 mph, weighing 5071 lbs, at an angular velocity of 1rad/s, with a force of 30,848 Newton’s, and accelerating at13.41 m/s^2. In addition, what would the size(dimensions) of this magnet have to be? Meaning, what magnet or contraption would have enough magnetic force to stop this car with characteristics I mentioned above.

Welcome to PF, Lancer.
Your question lacks an awful lot of specifications, starting with what sort of organization you have in mind. For my bucks, I'd go with magnetic calipers acting upon a standard rotor. As for power requirements, I have no idea.
 
I don't know what to suggest...can you give me examples of specifications for power requirements?
 
I just saw your post in the main forum, and see what you had in mind. (By the way, you shouldn't duplicate these.) I can't foresee any way in which this could work, but I'm not an expert.
 
:-( sigh okay thanks. U r more of an export than me.
 
Lancer2death said:
:-( sigh
Sorry... I hate to discourage anyone, but magnetism acts over a very short distance. You would need an electromagnet, rather than a permanent one, in your design (to enable deactivation for stuff like parking and towing). I don't know that any system could meet the power requirement. Your magnet would have to lie somewhere between an MRI scanner and a cyclotron. It would probably be heavier than the car itself, and your car's engine wouldn't be able to drive a generator large enough to power it.
Aleph posted a really good link in your General Engineering thread to show you what's involved.
 
Allright I understand more now. Thank you! U all r very helpful. I am less bummed out now that I know why it won't work.
 
Lancer2death said:
Im less bummed out now that I know why it won't work.

That's the good side of learning stuff. Don't let this instance discourage you from continuing to have neat ideas. There's no such thing as a bad idea, as long as it isn't pursued beyond the point of reason. Yours, for instance, is a very good one in principle; it just won't work magnetically. Lots of auto makers these days are incorporating anti-collision systems into their products. They're active rather than passive, though. Ultrasonic or radar sensors cause the onboard computer to electromechanically apply the brakes. It's taken them decades and millions of dollars to develop those, so don't feel badly that yours didn't make it off the launching pad the first time.
 
Oh wow that's so cool! I didn't know that. Well thank u. I will definitely continue to come up with great ideas now that I have found an awsome website
 
  • #10
Lancer2death said:
I will definitely continue to come up with great ideas now that I have found an awsome website

I look forward to seeing them. :smile:
 
  • #11
Danger said:
Welcome to PF, Lancer.
Your question lacks an awful lot of specifications, starting with what sort of organization you have in mind. For my bucks, I'd go with magnetic calipers acting upon a standard rotor. As for power requirements, I have no idea.

I think you mean eddy brake retarder, I might buy one for my own project, a 2200Nm with 4-550kw costs around $2500, shipping and customs another $800, weight around 400lb, enough to stop a bus.
 
  • #12
kazx9r said:
I think you mean eddy brake retarder

I didn't, actually, but it's a great system. Unfortunately, I don't know anything about the technical side of that. My thought was to use very powerful electromagnets rather than hydraulic cylinders to force standard brake caliper pucks against the rotor. :redface:
 

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