<span>The reason that things look wavy in the heat over a hot grill or stove is that the air temperature is not stable. Hot air naturally rises, so as air comes off the hot surface, it rises for a bit before rapidly cooling and sinking to be heated again. This constant mixing of hot and cool air produces vibration. This vibration affects how we see the light moving through the air, making it look wavy.</span>
If they align the object at the very edge of the ruler, the measurement in inaccurate. They would have to start the measurement at 0 to get an accurate measurement. When starting at the very edge, you are not taking into account the little bit of the ruler and it between the edge of the ruler and the 0 marker.
Some people start at the 1 cm mark (and then subtract 1 from their raw measurement) to make sure they have the most accurate measurement they can get.
I'm pretty sure that is what you are talking about. Hope this helps!!
Answer:
the answer is 27
Explanation:
1/2mv^2 = KE
if mass is 3, and velocity is 3 (3^2 = 9)
then KE increases by a factor of 27
one example is sound waves.
