Answer:
600m
Explanation:
30×20 at a constant speed is 600m.
D. used by the entire scientific community
B. more accurate system of measurement
Darker colors absorb heat, While lighter colors don't. If a house is painted black in Arizona, The black color will absorb the heat making the temperature inside the house very hot even with the AC on. If a house in Arizona is painted White, The heat will bounce off the White color, making the temperature inside the house cooler.
Hope this helps!
Answer:
the distance between adjacent fringes is increased by a factor o 2
Explanation:
To find how the distance between fringes is modified you can use the following formula for the calculation of the distance between fringes:

D: distance to the screen
d: distance between slits
λ: wavelength of the light
if d is decreased by a factor of 2, that is d'=1/2d, you have:

hence, the distance between adjacent fringes is increased by a factor o 2