A Unit Question: Flicking a Switch

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Discussion Overview

The discussion revolves around the physical concepts and units involved in calculating the effort required to flick a light switch, including considerations of force, impulse, work, and momentum. Participants explore various aspects of this problem, including the mechanics of the switch and the influence of different variables such as mass and velocity.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions whether to use force, impulse, or work to quantify the effort needed to flick a switch.
  • Another participant notes that there is a peak force required to overcome the switch mechanism, which is applied over a certain time, leading to impulse, and also mentions the work done on the spring of the switch.
  • A different participant introduces a scenario involving a projectile, seeking to determine the necessary velocity of an object with mass M to successfully flick the switch, and expresses uncertainty about the appropriate terminology and units for this varying quantity.
  • Another response suggests measuring the lightest object that can push down the switch using gravity, referencing F=MA for force and indicating that impulse would be relevant for velocity considerations.

Areas of Agreement / Disagreement

Participants express differing views on the appropriate physical quantities and units to consider, indicating that multiple competing perspectives remain without a consensus on the best approach to the problem.

Contextual Notes

Participants highlight the dependence on specific switch mechanisms and the variability in required measurements, which may affect the calculations and terminology used.

thepopasmurf
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If I wanted to work out the calculations for flicking a lightswitch, what units am I dealing with when I am determining how hard it is to flick the switch?

For example, I am sure that I wouldn't say it takes a certain amount of force because a large force over a short amount of time wouldn't do much. Is it impulse, or work?
 
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It depends what you want to measure.
There is a peak force needed to overcome the switch mechanism
You apply this force for a certain time so their is an impulse, you also have to do a certain amount of work on the spring holding the switch. Finally when the switch moves over into the new position it has a certain momentum.
 
Well, the problem I have in mind is flicking a light switch with a projectile. I want to know what velocity I have to give an object of mass M in order to flick a light switch. Of course different switches vary and I'm not sure what I should call this varying quantity and what unit it is
 
You could measure the lightest object needed to push down the light switch, using only gravity. F= MA and you know the force. As far as velocity, you would need to know the impulse.
 

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