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Name: Owen
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Question:
Does electricity have weight? I know that it is a force and therefore has no mass, but does that make it completely weightless? How is that possible?



Replies:
I think if you really push the issue, you might be able to claim electricity has some "weight". But it is so hard to measure because it is so small, and we are using terms in such imprecise ways that it is easy to get confused. It is on the order of a few electrons.

Electrical force comes from the repulsion of one electron by another. It might be labeled "electric force" or "magnetic force", but regardless, that is the source of the force. The electrons have weight. The force between them is "carried" by a photon, like light. A photon has a tiny amount of weight, or mass-- it is bent by a very strong nearby mass, say a star. But it is not bent a lot by the star's gravity, so the "weight" is very little. Too little for you to worry about in daily life.

Steve Ross


Owen,

Before considering whether something has weight, you must first know what weight is. Weight is a force. Weight is how much gravitational force an object feels. On the Earth, your weight is how hard the Earth pulls on you by means of gravitational force.

You must also know what mass is. Mass is a measure of how much material an object is made of. Any object far away from any planets or stars will have mass but not weight. It is not possible to have weight without mass. If something felt a force (such as gravity) but had zero mass, the object would experience infinite acceleration.

Before continuing, consider something. Think of a real-life example of electricity. Then ask yourself just what gravity would be pulling on. In most cases, the answer turns out to be the electrically charged particles that feel and exert the electric force. Quite often, electrons are the particles involved. "Electricity" flowing through a wire is not actually electricity. It is a set of electrons flowing through a wire, often called electric current. Static electricity on a balloon or on a wall is not electricity. It is too many or too few electrons, causing a build-up of electric charge. When a set of electric charges are close enough to notice each other, true electricity is the pushing or pulling between these particles due to their electric charges. The particles have weight, not the force between them.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College



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