Substance is some matter (it can be solid liquid or gas) that has its own properties.. everything in this world are substances...
like for example: the bread that we consume has - wheat ..yeast.. sugar.. salt or some other substances
Answer:
work output is always less than work input - the ratio is less than 1.
Explanation:
This principle comes from the fact that a machine or system cannot produce more work than is supplied to it, because this would violate the energy conservation law (work is a type of mechanical energy).
In theoretical machines called "ideal machines" the input work is the same as the output work, but these machines are only theoretical because in real applications there is always some type of energy loss, either in heat produced by a machine or processes for its operation, for this reason the output work is always less than the input work.
Regarding the ratio work output to work input:

because work input WI is always greater than work output WO.
Answer:
Volcanic eruptions cool down the planet
Explanation:
Volcanic eruptions actually cool the planet because the particles ejected from volcanoes shade incoming solar radiation. ... The small ash and aerosol particles decrease the amount of sunlight reaching the surface of the Earth and lower average global temperatures.
Hope this helps!!! :D