I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
We have the equation of motion 
, where v i the final velocity, u is the initial velocity, a is the acceleration and s is the displacement
Here final velocity, v = 40m/s
Initial velocity, u = 0 m/s
Displacement s = 2 m
Substituting 
So the baseball pitcher accelerates at 400m/
to release a ball at 40 m/s.
Revolution means orbiting around another body.
<span>A year is the time for a planet to complete one orbit around the Sun. 100% sure
</span>
Frost will disturb the smooth flow of air over the wing, unpleasantly
distressing its lifting competence. In other words, this spoils the even flow
of air over the wings, by this means decreasing lifting capability. Also, frost
may avoid the airplane from becoming flying at normal departure speed.
Polarized light light is unique in that it vibrates mostly in one direction.
Polarized mild waves are light waves in which the vibrations occur in a single plane. The process of reworking unpolarized light into polarized light is called polarization. There are a ramification of methods of polarizing mild.
Polarization is used for differentiating among transverse and longitudinal waves. Infrared spectroscopy makes use of polarization. it is used in seismology to take a look at earthquakes. In Chemistry, the chirality of organic compounds is tested the use of polarization strategies.
Refraction is the change in route of waves that takes place when waves tour from one medium to every other. . Light has a dual nature. as it has waves, sunlight passing via rainstorm makes a rainbow. however, while mild moves a sun mobile, it can provide strength as a series of very small bursts. particles of count number have names together with the proton, electron and neutron.
Learn more about lights here:-brainly.com/question/19697218
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