How do you capture and use energy from treadmill machines and rowing machines and exercise machines?
Kelly M. Knox has written: 'Energy cost of walking with and without arm activity on the Cross Walk dual motion cross trainer' -- subject(s): Energy metabolism, Exercise for women, Physiological aspects, Physiological aspects of Exercise for women, Physiological aspects of Walking, Treadmill exercise tests, Walking
It is wrong to say machines create energy. Machines have to be given energy to make them effective. This could be electric energy, solid liquid or gaseous energy, thermal energy, mechanical energy (like a flywheel for example). It may be possible to design machines which will search for their energy by themselves, some robots may already have achieved. Remember we humans are also machines, but we get our energy from digesting food.
There is no single answer. Velocity is relative, and that means that the kinetic energy of a body also is relative. To calculate the kinetic energy you have to choose a reference frame, and the answer will be different depending on if you choose the person, the belt of the treadmill or the moon. Neither answer is more right or wrong than any other.
Treadmills operate by muscle force. Muscles are powered by the conversion of sugars to energy and carbon dioxide. More energy is used and more carbon dioxide is released when people exercise. People exhale the carbon dioxide. So treadmill use results in the emission of more carbon dioxide than would be released by a person at rest.
Energy conversion I would say means converting say thermal energy to mechanical, or mechanical to electrical, or other conversions you can think of. Now some machines do this, like electrical generators, or electric motors which is the same but in reverse. Other machines are just mechanical, like a gearbox for example, mechanical energy in and mechanical energy out. So the word machine is more general, energy conversion devices are a sub-set of machines.
The process of photosynthesis requires carbon dioxide, energy and light. The function of the chloroplast is to capture energy from light in order to photosynthesis (make food using light). Inside a chlorplast are hundreds of light absorbing "buckets" called photsystems which capture and absorb light energy. The energy from the light colletively creates energy which goes on to be used in the stages of photsynthesis.