Alveoli are tiny balloon shaped structures and are the smallest passageway in the respiratory system. The alveoli are only one cell thick, allowing the relatively easy passage of oxygen and carbon dioxide (CO2) between the alveoli and blood vessels called capillaries.
Answer:
5
Explanation:
Number of habitable planets = 1000
Fraction of planet with life = 1/10
Fraction of planet with life and civilization (before) = 1/4
Fraction of planet with life and civilization (now) =1/5
Therefore multiplying we have:
1000×1/10×1/4×1/5 = 5
Answer: E/4 ( one - fourth of it electric field)
Explanation:
The electric field of a point charge is given below as
E =kq/r²
E = electric field,
K = electric constant
q = magnitude of electric charge
r = distance between point charge and electric field.
It can be seen that only E and r are the only variable here and also, E is inversely proportional to r²
Which implies that
E = k/r² , k = E × r²
E1 ×(r1)² = E2 × (r2)²
Let E1 = E, r1 =1, r2 = 2 and E2 =?
Let us substitute the parameters
E × 1 = E2 × 2²
E × 1 = E2 × 4
E = E2 × 4
E2 = E/4
Which implies that the electric field at the second distance (r =4) is one fourth of the initial electric field.