(i) |α| = 235.6rad.s / 0.502s = 469 rad/s²
(ii) tang a = α*r = 469rad/s² * 0.12m / 2*11 = 2.56 m/s²
We can solve the problem by using Snell's law, which states

where

is the refractive index of the first medium

is the angle of incidence

is the refractive index of the second medium

is the angle of refraction
In our problem,

(refractive index of air),

and

(refractive index of carbon disulfide), therefore we can re-arrange the previous equation to calculate the angle of refraction:

From which we find
Answer:
1 m/s² down
Explanation:
"Calculate the acceleration of the elevator, and find the direction of acceleration."
Sum of forces in the +y direction:
∑F = ma
N − mg = ma
0.9 mg − mg = ma
-0.1 mg = ma
a = -0.1 g
a = -1 m/s²
An electron shell can hold 2(n^2) electrons (technically) where n is the shell number, i.e. shell 1 can hold 2, shell 2 can hold 8, 3 holds 18 and so on.
The atomic number of Nitrogen is 7, i.e. it has 7 electrons (to match its 7 protons, assuming it isn't an ion).
With the atomic number, you simply start from shell 1 and work out. So we put 2 electrons in shell 1, leaving us with 5 left. Shell 2 can hold 6 so we can fit all 5 in.
In other words, you should have 2 electron shells on the atom, shell 1 with 2 e- and shell 2 with 5 e-.
The frictional force between two bodies depends mainly on three factors: (I) the adhesion between body surfaces
(ii) roughness of the surface
(iii) deformation of bodies.
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