The wavelength (λ) of the photon : <u>5.106.10⁻⁷ m</u>
<h3>Further explanation </h3>The photoelectric effect is an electron coming out of a metal because of electromagnetic radiation
One type of electromagnetic radiation is light
Electrons can come out of metal because they absorb electromagnetic energy radiated on metals. There is also kinetic energy released from metal, which is according to the equation:
fo = the threshold frequency of electromagnetic waves
Radiation energy is absorbed by photons
The energy in one photon can be formulated as
Where
E = energy of light, J
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves, Hz
f = c / λ
c = speed of light
= 3.10⁸
λ = wavelength
The radiation emitted by the nitrogen and absorbed by an electron
E = h. f
E = 6,626.10⁻³⁴. 8.88 × 10¹⁴
E = 5.839.10⁻¹⁹ J
Two-thirds of the energy previously absorbed and emitting a photon
E photon = 2/3 x E electron
E photon = 2/3 x 5.839.10⁻¹⁹ J
E photon = 3.893.10⁻¹⁹ J
Electromagnetic radiation with wavelength of 745 nm
The energy of a photon
The equation E = hf
the approximate energy of a photon
The equation for photon energy
the wavelength of a photon whose energy is twice
Answer:
(507 nm)
Explanation:
First of all let's calculate the energy of the photon absorbed by the electron, This is given by
where
h is the Planck constant
is the frequency of the photon
Substituting,
The energy of the second photon, the one emitted when the electron drops to the intermediate energy level, is 2/3 of this energy:
The relationship between the energy of the photon and its wavelength is
where c is the speed of light. Solving for , we find the wavelength:
Answer:
Explanation:
Total energy of a satellite in an orbit , h height away
= - GMm /2 ( R + h )
When h = 380 km
Total energy of a satellite =
= - 13.25 x 10¹⁰ J
When h = 190 km
Total energy of a satellite =
= - 13.63 x 10¹⁰ J
Diff
= 38 x 10⁸ J Energy will be required.
Answer:
Explanation:
The equation that relates heat Q with the temperature change of a substance of mass <em>m </em>and specific heat <em>c </em>is
.
We want to calculate the final temperature <em>T, </em>so we have:
Which for our values means (in this case we do not need to convert the mass to Kg since <em>c</em> is given in g also and they cancel out, but we add to our temperature in
to have it in
as it must be):
Answer:
<em>0.45 mm</em>
Explanation:
The complete question is
a certain fuse "blows" if the current in it exceeds 1.0 A, at which instant the fuse melts with a current density of 620 A/ cm^2. What is the diameter of the wire in the fuse?
A) 0.45 mm
B) 0.63 mm
C.) 0.68 mm
D) 0.91 mm
Current in the fuse is 1.0 A
Current density of the fuse when it melts is 620 A/cm^2
Area of the wire in the fuse = I/ρ
Where I is the current through the fuse
ρ is the current density of the fuse
Area = 1/620 = 1.613 x 10^-3 cm^2
We know that 10000 cm^2 = 1 m^2, therefore,
1.613 x 10^-3 cm^2 = 1.613 x 10^-7 m^2
Recall that this area of this wire is gotten as
A =
where d is the diameter of the wire
1.613 x 10^-7 =
6.448 x 10^-7 = 3.142 x
=
d = 4.5 x 10^-4 m = <em>0.45 mm</em>