Pendulum is not a perpetual motion machine? Why?

Perpetual motion machine. yǒng dòng jī]

A perpetual motion machine is a kind of machinery that can continuously move and do work externally without the need for external input energy, energy or only one heat source.

A machine that does not consume energy and can do work forever violates the law of conservation of energy, so it is called "the first type of perpetual motion machine". In the absence of temperature differences, a machine that continuously absorbs heat from seawater or air in nature and continuously transforms it into mechanical energy violates the second law of thermodynamics, so it is called "second type of perpetual motion machine".

These two types of perpetual motion machines are concepts that violate the current objective scientific laws and cannot be manufactured.

When energy is transformed from one form to another, it is absolutely impossible to convert 100% of the time into that form. For example, the heat energy produced by substances rubbing against each other.

There is no such thing as a perpetual motion machine, and the pendulum also has its own useful life.

Because a perpetual motion machine does not require external energy, while a pendulum requires artificial tightening of the mainspring to give it mechanical energy.

The perpetual motion machine is never-ending.

1 If the pendulum is a perpetual motion machine, it should meet the definition of a perpetual motion machine: a perpetual motion machine is a kind of machinery that can continuously move and do work externally without the need for external input energy.

2 This type of perpetual motion machine violates the law of conservation of energy.

3 The ideal state of absolute frictionless and frictionless resistance does not exist in nature.

4 The pendulum is constantly moving, and it is necessary to overcome weak resistance. Therefore, a small amount of energy needs to be provided from the outside world. Does not meet the definition of a perpetual motion machine.

So the pendulum does not belong to a perpetual motion machine.

I bought a clock before, it's very interesting, the clock is an elephant shape, the foot is the pendulum, its pendulum is made of levers, the top is an arc structure with an opening downward, and the lever is an arc structure with an opening upward, not the kind of old-fashioned winding pendulum, as long as the clock is hung on the wall, gently pushed, it can keep swinging, which does not meet the conditions for the perpetual motion machine to do work externally, but if it is magnified n times, wound the wire, put it in a vacuum ultra-low temperature environment, and initially do work for it, Then it can't keep doing the cutting of magnetic inductance line motion, in other words, it has the conditions to do work, even if it can't move forever but the work done should be able to exceed the work that pushed it at the beginning, although its gravity also does work, but the gravitational potential energy is not pushed to it from the beginning, back to the beginning of the problem, pushing the pendulum only needs to do a very small amount of work, but it may go on forever, this is still the case of air resistance and temperature influence, the work done should be much greater than the work given to it at the beginning, what's going on? There is also a scene that just suddenly thought, if a large enough permanent magnet is placed on the ground in a vacuum environment, and a magnet that repels it is dropped from a high enough place, when approaching the permanent magnet, it turns kinetic energy into gravitational potential energy due to repulsion, and because there is no air resistance, will it always do reciprocating up and down motion, at this time, connect the moving magnet to a copper wire, and the induced current will be generated, and it has the ability to do work, so where does the work come from?