Air pressure is the wi get of air molecules pressing down on the earth. The pressure of the air molecules changes as you move upward from sea level into the atmosphere, the highest pressure is at sea level where the density of the air molecules is the greatest.
Density is defined as (mass) per unit (volume). So in order to calculate
the density of a glob of some substance, you pretty much have to measure
its mass and its volume.
Answer:
b. 0.25cm
Explanation:
You can solve this question by using the formula for the position of the fringes:

m: order of the fringes
lambda: wavelength 500nm
D: distance to the screen 5 m
d: separation of the slits 1mm=1*10^{-3}m
With the formula you can calculate the separation of two adjacent slits:

hence, the aswer is 0.25cm