Well you need to have lots of heat
Most of the substances have higher density in solid state. When we heated solids it change its state to liquid. After a few minutes the liquid will boil and after that it will change to gas. Gaseous state of matter has the lowest density. From this we can conclude that density decreases with increase in temperature.
Note the point: Water has higher density in 4℃, at its liquid state
That's the <em><u>speed</u></em> of the wave.
("Velocity" is not a good way to say it, because 'velocity' always needs a direction,
and neither frequency nor wavelength tells anything about direction.)
Answer:
C!
Explanation:
Cold fronts generally advance at average speeds of 20 to 25 mph. toward the east — faster in the winter than summer — and are usually oriented along a northeast to southwest line.