Science Buddies: "Ask an Expert"

Want some more ideas.
Our group has gone through the idea that if we place somethng in vaccum it continues to be in motion so we have an idea to use that phenomenon in generating energy .. Can it be possible?

RRpunjwani,

Welcome to Science Buddies, and thank you for your question. Can you please explain what you mean by something continues to be in motion in placed in a vacuum? What object are you considering and what vacuum? Do you mean to create a vacuum inside a container or are you referencing the vacuum of outer space?

Any object on Earth moving through the atmosphere (or a fluid of any given density) will experience aerodynamic drag to some degree. This is friction generated from the interaction of the surface of your object with air/fluid molecules moving around it, slowing and eventually stopping any motion unless counteracted by another force equal to or greater than the drag force. A vacuum is defined as a volume devoid of matter, including air. If an object were to be placed in a theoretically perfect vacuum, aerodynamic drag forces would be zero and any force applied to cause motion would not be counteracted by drag. The vacuum itself doesn’t apply a force to cause or continue motion. If you are considering, say a fly wheel placed in a vacuum tank and somehow set up to spin and supply electricity, the aerodynamic drag forces are actually quite small compared to the magnetic drag on an electromagnetic generator or the mechanical friction from belts, pulleys, bearings, etc...

However, it would be an interesting science experiment to determine how much efficiency, if any, can be gained by placing a generator in a vacuum. Please provide greater detail of your experiment so we can give better advice.

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