Answer:
Explanation:
The energy of a photon is given by the equation
, where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of
.
We also know that frequency and wavelength are related by
, so we have
, where c is the <em>speed of light</em>.
We will want the number of photons, so we can write

We need to know then how much energy do we have to calculate N. The equation of power is
, so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be
.
Putting this paragraph in equations:
.
And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:

ELECTROSTATIC:
relating to stationary electric charges or fields as opposed to electric currents.
NEUTRAL:
nor negative nor positive/having no charge
POSITIVELY CHARGED:
positive charge occurs when the number of protons exceeds the number of electrons
NEGATIVELY CHARGED:
negative charge occurs when the number of electrons exceeds the number of protons.
COULOMB:
SI unit for electric charge. One coulomb is equal to the amount of charge from a current of one ampere flowing for one second.
MICROCOULOMB:
a unit of electrical charge equal to one millionth of a coulomb.
NANOCOULOMB:
Nanocoulombs are a unit of charge 1,000,000,000 times smaller than Coulomb.
CONSERVATION OF CHARGE:
constancy of the total electric charge in the universe or in any specific chemical or nuclear reaction
QUANTISATION OF CHARGE:
Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge.
Answer:
Height will be 3.8971 m
Explanation:
We have given that radius of the solid r = 1.60 m
Mass of the solid disk m = 2.30 kg
Angular velocity 
Moment of inertia is given by 
Transnational Kinetic energy is given by
as we know that v = 
So 
Rotational kinetic energy is given by 
Potential energy is given by mgh
According to energy conservation


Answer:
Δu=1300kJ/kg
Explanation:
Energy at the initial state

Is saturated vapor at initial pressure we have

Process 2-3 is a constant volume process

The overall in internal energy
Δu=u₁-u₃
We replace the values in equation
Δu=u₁-u₃

Δu=1300kJ/kg
Answer:
(a) 4.0334Ω
(b)parallel
Explanation:
for resistors connected in parallel;

Req =3.03Ω , R1 =12.18Ω



R2=1/0.2479
R2=4.0334Ω
(b)parallel connection is suitable for the desired total resistance. series connection can not be used to achieve a lower resistance as the equation for series connection is.
Req = R1+R2