Answer:
15.76°
Explanation:
Hi!
Let C~ = A~ + B~
Then
C~ dot A~ = |C| |A| cos Ф
C~ dot A~ = (A~ + B~) dot A~ = |A|^2 + |B| |A| cos(120)
Therefore
cos Ф = (|A| + |B| cos(120)) / |C| = 15.65/|C|
and
|C|^2 = |A|^2 + |B|^2 + 2 |B| |A| cos(120)
|C| = 16.261
cos Ф = 15.65/16.261
Ф = 15.76°
Answer:
Explanation:
a ) The angle between the polarization axis of two adjecent sheet
= 90 / 3 = 30 degree.
The formula for intensity of polarised light from unpolarised light ( first transmission
I₁ = I₀ /2
I₀ is intensity of unpolarised light and I₁ is intensity of light after first time polarization .
The relation of I₁ and I₂ is as follows
I₂ = I₁ cos²30
= I₀/2 x3/4
=3 I₀/8
Relation between I₃ and I₂ is as follows
I₃ = I₂ cos²30
= 3I₀ / 8 x 3/4
= 9 I₀ / 32
= 0 .28 I₀
In case of stack of 4 plates
angle between two plates = 90/4 = 22.5 degree
I₁ = I₀ /2
I₂ = I₁ cos²22.5
= I₀ /2 x .85
I₃ = I₂ cos²22.5
= I₀ /2 x .85 x .85
= .36 I₀
Answer:
it is safe to stand at the end of the table
Explanation:
For this exercise we use the rotational equilibrium condition
Στ = 0
W x₁ - w x₂ - w_table x₃ = 0
M x₁ - m x₂ - m_table x₃ = 0
where the mass of the large rock is M = 380 kg and its distance to the pivot point x₁ = 850 cm = 0.85m
the mass of the man is 62 kg and the distance
x₂ = 4.5 - 0.85
x₂ = 3.65 m
the mass of the table (m_table = 22 kg) is at its geometric center
x_{cm} = L/2 = 2.25 m
x₃ = 2.25 -0.85
x₃ = 1.4 m
let's look for the maximum mass of man
m_{maximum} =
let's calculate
m_{maximum} =
(380 0.85 - 22 1.4) / 3.65
m_{maximum} = 80 kg
we can see that the maximum mass that the board supports without turning is greater than the mass of man
m_{maximum}> m
consequently it is safe to stand at the end of the table