Distance between successive compression is wavelength !
so answer is D !!
Lubricant is a type of oil. It smoothes surfaces. Meaning anything rubbing against the other object wont produce enough heat, which is what creates friction. Its an ideal tool to use for a lot of things.
I hope this helps :)
Your being on the moon has no effect on the moon's
gravitational field strength, or on the Earth's for that
matter.
However, YOU notice a change on YOU when YOU move
from one to the other, because of the effect of the gravitational
field strength on you and your internal organs.
If you could stand on the moon, you would experience an incredible
sense of lightness, since the forces of attraction between the moon
and anything else are only 16% as great as the same forces are on
Earth.
Time, Frequency, and Intensity.
Answer:
they move in an orbit of a fixed size and also energy