is this perpetual motion?

Question

ok... say i hooked an electrical generator up to a motor so that the motor would spin the generator to make electricity... now say i made it so that the electricity output from the generator powered the motor and then this would just go on and on and on... is that perpetual motion?

if the power output wouldnt be enough to power the motor to make the machine go forever, then couldn't you just do that thing where you put a small gear next to a big gear, and then the small gear spins really fast?

have people done this before? i mean... if it works then why wouldn't we use this to power the world!!! like gosh!!! one for each house (or 10 whatever it takes..) i mean free power!!! (if it works)

Answer 1

The second law of thermodynamics says that no matter how much pwoer you put into a motor, you will never get as much out. Even if you connected it up to a gear system, by speeding up the spin, you lose the torque (and some energy is lost as heat) so it wouldn't be able to spin a generator with as much force. So no, this does not work. I know people who have tried this. It failed them. You simply will not get enough energy out of a motor to generate that same amoutn of energy on any possible generator.

Answer 2

You have invented a perpetual motion system. Its a very inovative idea.
Newton's law of inertia indicates that if you apply power to an object ,it will move with that same power during its motion and would continue to oscillates with the same motion forever unless another structure in its path Hinders the motion.

The micromass structure that hinders the motion is called resistance which is basically friction.
And because of friction we cannot obtain the same power continuously to carry the same amount of motion.
That is stated by the second law of thermodynamics = You cannot get more motion out then what you put in. In other words you can't get nothing For nothing.

Therefore your generator would generate less and lesss power ,so your motor would eventually peter out since the motor would be getting less and less power feed back till it dies out.

It was an interesting idea .you have the imagination and ability to be a Physisit.

Answer 3

The purpose of an electric motor is to 'convert' electrical energy to mechanical energy. The purpose of an electrical generator is to 'convert' mechanical energy into electrical energy. Neither process is 100% efficient and energy is lost over a period of time. Feel an electric motor or generator and it is warm to the touch because energy is lost as heat due to the resistance of wires and energy is also lost due to bearing friction and windage. For a combination motor and generator to achieve perpetual motion you would have to have a fox that chases its tail without expending energy or tiring forever. If you wire a motor to a generator they will just sit there until you add electrical or mechanical energy which will soon be lost if not constantly supplied.

Answer 4

The 2nd Law of Thermodynamics has little to do with the question only if it is to state that energy can neither be created nor destroyed, only converted. In that case, if the efficiency of the generator and motor were 100% each (ZERO FRICTIONAL LOSSES), you could very well have perpetual motion but since you cannot exceed 100% efficiency, your net gain would be 0 and you couldn't scavenge the excess since there wouldn't be an excess.

Answer 5

Yes, it would be perpetual motion, which should immediately suggest to you that it wouldn't work that way.

Try using numbers to see why.

Say a generator has an output of 100W. In order to get 100W out, it will require the power of 120W to turn it, meaning its about 83% efficient.

So now the motor that you have to turn the generator will have to output 120W. But to output 120W from a motor you need to input 150W of power, making it 80% efficient.

So how can you drive a motor requiring 150W when you only have 100W?

How can anyone tell that the full input power is not reaching the output of a device? Did you ever wonder why the motor or generqator get hot? Heat is the biggest loss of power but other forms such as electrical eddying are also contributators to power loss.

Theres also that pesky factor called "entrophy", which loosely says that no real process can be 100 percent efficient. Ever.

Every machine works because it takes energy from one source and outputs a lesser amont of energy to another.

Even a solar cell takes in 1 Watts of sunlight power while only outputting 0.6 Watts of electrical power. In other words, there's no free lunch, or free energy, anywhere.

Answer 6

The problem is- It won't work. That is the idea of perpetual motion. Where motion continues due to enough power coming out of it-to keep it going permanently.

The configuration has been tried, and energy is lost due to heat and friction and decay of battery, and cannot generate enough power to keep it going. It always takes more power being put in than put out.

Jim

Answer 7

if the power produced by the generator is not enough to power the motor it will stop in a few seconds...............but the motor loses power creating friction so it can produce electricity.......it is a perpetual motion but it's not very practical

Answer 8

as far as i know there is no such thing as a perpetual motion machine. everything you say is true. the only problem is that it must be maintained , someone has to put gas in the generator , or change the gears , no machine as far as i know has ever been invented ,even nuclear powered machines must be maintained .

Answer 9

Won't work. Every time you change energy (IE: electrical to mechanical to electrical and so on) you loose energy to heat, friction, and electrical inefficiency.

Answer 10

In fact the answer to the question is NO without even reading the rest.....