Answer:
The thermal energy is carried by electromagnetic waves
Explanation:
There are three types of transfer of heat (thermal energy):
- Conduction: conduction occurs when two objects/two substances are in contact with each other. The heat is transferred from the hotter object to the colder object by the collisions between the molecules of the two mediums.
- Convection: convection occurs when a fluid is heated by an external source of heat. The part of the fluid closer to the heat source gets warmer, therefore it becomes less dense and it rises, and it is replaced by the colder part of the fluid, which is colder. Then, this part of fluid is heated as well, so it gets warmer, it rises, etc.. in a cycle.
- Radiation: radiation occurs when thermal energy is carried by electromagnetic waves. Since electromagnetic waves do not need a medium to propagate, this is the only method of heat transfer that can occur through a vacuum (so, in space as well).
Indeed, the Sun emits a lot of electromagnetic radiation, which travels through space and eventually reaches the Earth, heating it.
Complete question is;
The energy flow to the earth from sunlight is about 1.4kW/m²
(a) Find the maximum values of the electric and magnetic fields for a sinusoidal wave of this intensity.
(b) The distance from the earth to the sun is about 1.5 × 10^(11) m. Find the total power radiated by the sun.
Answer:
A) E_max ≈ 1026 V/m
B_max = 3.46 × 10^(-6) T
B) P = 3.95 × 10^(26) W
Explanation:
We are given;
Intensity; I = 1.4kW/m² = 1400 W/m²
Formula for maximum value of electric field in relation to intensity is given as;
E_max = √(2I/(ε_o•c))
Where;
ε_o is electric constant = 8.85 × 10^(-12) C²/N.m²
c is speed of light = 3 × 10^(8) m/s
Thus;
E_max = √(2 × 1400)/(8.85 × 10^(-12) × 3 × 10^(8)))
E_max ≈ 1026 V/m
Formula for maximum magnetic field is;
B_max = E_max/c
B_max = 1026/(3 × 10^(8))
B_max = 3.46 × 10^(-6) T
Formula for the total power is;
P = IA
Where;
A is area = 4πr²
We are given;
Radius; r = 1.5 × 10^(11) m
A = 4π × (1.5 × 10^(11))² = 2.82 × 10^(23) m²
P = 1400 × 2.82 × 10^(23)
P = 3.95 × 10^(26) W
Answer:
c) At a distance greater than r
Explanation:
If G= Gravitational constant
M= Mass of earth
r= distance from earth center
then orbital speed is ;
v = 
==> v²=GM/r
If speed of first satellite = V₁
==> V₁² = GM/r
==> r = GM/V₁²
If speed of second satellite say V₂ is less than V₁ then square of V₂ will be less than square of V₁ , and hence GM will be divided by less number in case of second satellite, and hence will give greater value of r as compared to first satellite.
So our answer is c
2Fe(s) + O2 -> 2FeO(s)
<span>2 'Fe' atoms on both sides </span>
<span>2 'O' atoms on both sides</span>
