Answer:
and 
Explanation:
The wavelength of a visible light is 727.3 nm.
The formula is as follows :
f is the frequency of the visible light
Energy of a photon is given by :
E = hf, h is Planck's constant
Red color has a frequency of 
and energy per photon is 
.
The quantity of heat must be removed is 1600 cal or 1,6 kcal.
<h3>Explanation : </h3>
From the question we will know if the condition of ice is at the latent point. So, the heat level not affect the temperature, but it can change the object existence. So, for the formula we can use.
If :
- Q = heat of latent (cal or J )
- m = mass of the thing (g or kg)
- L = latent coefficient (cal/g or J/kg)
<h3>Steps : </h3>
If :
- m = mass of water = 20 g => its easier if we use kal/g°C
- L = latent coefficient = 80 cal/g
Q = ... ?
Answer :
So, the quantity of heat must be removed is 1600 cal or 1,6 kcal.
<u>Subject : Physics </u>
<u>Subject : Physics Keyword : Heat of latent</u>
Answer:
y = 2.74 m
Explanation:
The linear thermal expansion processes are described by the expression
ΔL = α L ΔT
Where α the thermal dilation constant for concrete is 12 10⁻⁶ºC⁻¹, ΔL is the length variation and ΔT the temperature variation in this case 20ªc
If the bridge is 250 m long and is covered by two sections each of them must be L = 125 m, let's calculate the variation in length
ΔL = 12 10⁻⁶ 125 20
ΔL = 3.0 10⁻² m
Let's use trigonometry to find the height
The hypotenuse Lf = 125 + 0.03 = 125.03 m
Adjacent leg L₀ = 125 m
cos θ = L₀ / Lf
θ = cos⁻¹ (L₀ / Lf)
θ = cos⁻¹ (125 / 125.03)
θ = 1,255º
We calculate the height
tan 1,255 = y / x
y = x tan 1,255
y = 125 tan 1,255
y = 2.74 m
Answer: The normal of the plane must be parallel to the electric field vector.
Explanation:
the normal to the surface is defined as a versor that is perpendicular to the plane.
Now, if the angle between this normal and the line of the field is θ, we have that the flux can be written as:
Φ = E*A*cos(θ)
Where E is the field, A is the area and θ is the angle already defined.
Now, this maximizes when θ = 0.
This means that the normal of the surface must be parallel to the electric field
