You are an employee of the city of Chicago. A city official declares that all cables holding traffic lights in the city should b

Question

1 month ago

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You are an employee of the city of Chicago. A city official declares that all cables holding traffic lights in the city should b

e exactly horizontal and asks you to direct the project. What should be your reply?
A. That's impossible, because according to Newton's Second Law, there must be an upward component of the tension in the cable that balances the weight of the traffic light, and therefore, the cable can never be exactly horizontal.

B. No problem. All we have to do is increase the horizontal tension in the cable.

C. No problem. All it takes is a pay raise.

D. That's impossible, because by Newton's Third Law, the cable pulls horizontally on the poles with a force of the same magnitude force as the force with which the poles pull on the cable. Therefore, if the horizontal component of the tension is too large, it will pull the poles inward toward the cables.

Physics

1 answer:

Sav [3.1K] · Answer 1 · 2026-02-28T00:53:33+03:00

If you have experience living in Chicago, then option C may resonate with you. Newton's second law, expressed as F = ma, is not applicable in this scenario concerning acceleration. The third law of Newton refers to the well-known action/reaction principle. Provided the poles are sufficiently anchored and possess flexural strength that can handle the tension from the wire, then option D becomes applicable. This leaves option B available. The solution is straightforward; we simply need to increase the horizontal tension in the cable.