The discussion centers on Richard Feynman's explanation of perpetual motion machines, specifically in the context of weight-lifting machines. Feynman defines a perpetual motion machine as one that, after lifting and lowering weights, returns to its original condition while having lifted a weight, thus seemingly creating energy. Participants clarify that such machines violate the law of conservation of energy, emphasizing that no machine can operate without an external energy source. The conversation also touches on misconceptions surrounding perpetual motion and the classification of these machines into three types, with the first type being impossible according to thermodynamic principles.
PREREQUISITESStudents of physics, educators explaining energy concepts, engineers interested in mechanical systems, and anyone curious about the principles of energy conservation and perpetual motion machines.
CWatters said:Aleoa.. Can I check you understand that you understand something...
In the following I will assume there is no friction.
If the net torque on the balance is zero this means the balance is not accelerating. That does not mean the balance is stationary.
If the balance starts off stationary then it will remain stationary.
If the balance starts off rotating at a constant angular velocity it will continue rotating at a constant velocity. Even though it keeps rotating this does not mean it is a perpetual motion machine.
It's possible to make a machine that keeps rotating forever (eg two stars in orbit around each other) but this is not what scientists mean by a perpetual motion machine. To be a perpetual motion machine it must also be capable of doing some work even if that's small. Otherwise it is useless.
Yes.Aleoa said:If i apply the formula of the moment , what i note is that a balanced lever is balanced in every possible angle of the lever with the ground. Is this true in the ideal case ?
CWatters said:Yes.
CWatters said:...by its regenerative braking system.
I said "regenerative braking system" for a reason. Perhaps I should have said "ideal regenerative braking system".bland said:It couldn't be in the same state anyway because of the brakes would generate heat because.