Answer:
Height above a surface
Explanation:
Gravitational potential energy is the energy which an object possesses due to its position above a surface.
It is also the amount of work a force has to do in order to bring an object from a particular position to a point of reference.
It is given mathematically as:
P. E. = m*g*h
where m = mass of the body
g = acceleration due to gravity
h = height above a surface
m*g represents the weight of the object.
Hence, Gravitational potential energy is the product of an object's weight and its height above a surface/reference point.
Probably wikipedia or unreliable internet sources in general
Answer:
I₂ = 25.4 W
Explanation:
Polarization problems can be solved with the malus law
I = I₀ cos² θ
Let's apply this formula to find the intendant intensity (Gone)
Second and third polarizer, at an angle between them is
θ₂ = 68.0-22.2 = 45.8º
I = I₂ cos² θ₂
I₂ = I / cos₂ θ₂
I₂ = 75.5 / cos² 45.8
I₂ = 155.3 W
We repeat for First and second polarizer
I₂ = I₁ cos² θ₁
I₁ = I₂ / cos² θ₁
I₁ = 155.3 / cos² 22.2
I₁ = 181.2 W
Now we analyze the first polarizer with the incident light is not polarized only half of the light for the first polarized
I₁ = I₀ / 2
I₀ = 2 I₁
I₀ = 2 181.2
I₀ = 362.4 W
Now we remove the second polarizer the intensity that reaches the third polarizer is
I₁ = 181.2 W
The intensity at the exit is
I₂ = I₁ cos² θ₂
I₂ = 181.2 cos² 68.0
I₂ = 25.4 W
Explanation:
Given that,
(a) Frequency, 
All electromagnetic wave moves with the speed of light. It is given by :


(b) Frequency, 
All electromagnetic wave moves with the speed of light. It is given by :


Hence, this is the required solution.
Answer:
(a) The spring constant is 426N/m
(b) The mass is 5.65kg
Explanation:
(a) Energy stored in the spring (E) = 3.6J, extension (e) = 0.13m
E = 1/2Ke^2
3.6 = 1/2 × K × 0.13^2
K (spring constant) = 3.6×2/0.0169 = 426N/m
(b) F = Ke = 426 × 0.13 = 55.38N
Assuming the maximum acceleration (a) is 9.8m/s^2
Mass (m) = F/a = 55.38/9.8 = 5.65kg