|MadSci Network: Physics|
Hi, Can friction generate electricity? Thats a good question. The answer to your question is yes and no. Here's why: Why Yes? : If you rub a piece of plastic on your hair or on wool you would generate what is known as static electricity. What you do while rubbing the plastic is generate a charge on its surface. This charge can then flow into an object that has the opposite charge. So by rubbing (friction) you can create charges which are responsible for generating electricity. If you can rub a very large number of particles, you may even be able to see a small spark. Thats what creates lightning. The small particles in clouds rub against each other at very high speeds. This creates a lot of charge, which then flows down to the nearest object (another cloud or earth). Some materials when struck against each other also produce a spark. Thats how fire was made in the olden times. You struck two stones, or a stone with a metal to create a spark, from which you started a fire. So you can create electricity by friction. Why No? : Friction usually produces a lot of heat. So if you tried to produce a lot of electricity in this way, you would produce a lot more heat than electricity. And that would be a terrible waste!! Secondly, it is not yet been able to use the static electricity produced by friction. If it were, than our lights and televisions would be running just on lightning!! The electricity produced by static charges is usually very minute (small) and not practical to use as a source of power. Also the power produced does not last very long. Lightning for example, may be able to power a 100W electric bulb for about a month. However, it takes only a fraction of a second for lightning to strike. And we have no batteries that can be charged that fast. So till now it has not been possible to use friction to produce electricity. I hope that helps. Nauzad Tantra
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