1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
olchik [2.2K]
1 year ago
8

what is the energy of a photon with a wavelength of 21 nm? hint: treat the planck constant as 7 x 10-34 j*s

Physics
1 answer:
Sladkaya [172]1 year ago
5 0

The energy of a photon is 10⁻¹⁷ J

The quantum e.m radiation is known as photon.

photon energy is the energy carried by a single photon.

The energy of  a photon is inversely proportional to the wavelength.

we can measure the energy of photon using Einstein's equation.

E=hv      (equation1.)

wavelength, λ= 21 nm = 21×10⁻⁹m

planck's constant, h= 7 x 10-34 j-s

v = frequency

as we know,

λv = c      (equation2.)

here v is the frequency

speed of light, c (c = 3×10⁸m/s)

using the value of 2 in 1 we get

E =hc/λ

E = 7×10⁻³⁴ₓ3ₓ10⁸/21ₓ10⁻⁹

E = 10⁻¹⁷ J

The energy of a photon is 10⁻¹⁷ J

To know more about energy of a photon :

brainly.com/question/11161069

#SPJ4

You might be interested in
Question 1: The wavelength of a wave is 0.5 meters, and its period is 2 seconds. What is the
jek_recluse [69]

Answer: I believe it’s .25 m/s

Explanation: the speed is measured distance/ time. Which is .5 meters/ 2 seconds =0.25

7 0
3 years ago
In the Zeeman effect, the energy levels of hydrogen are split by a magnetic field. Each state with a different value of mlml has
Nikolay [14]

Answer:

the Zeeman effect without spin is three lines

Explanation:

The Zeeman effect is the result of the interaction of the magnetic field with the orbital angular momentum of the electrons, if we do not take the spin into account it is called the Normal Zeeman effect.

Therefore we only take into account the orbital moments (m_l) of the transition, from the selection rules of the refreshed harmonics, only the transition with

             \Delta m_l = 0, ± 1

            ΔE \DeltaE = \mu_B \ \Delta  m_l \ B

Let's analyze for the case of the Hydrogen atom

For a transition between levels n = 1 and n = 2 the values ​​of m_l are n_f = 1 m_l = 0 and for n₀ = 2  m_l = 0, 1

so we only have two lines.

For transition n_f = 2 and n₀ = 3

n_f = 2    m_l = 0, 1

n₀ = 3      m_l = -1, 0, 1

There are only two lines plus the central line, so there are three spectral lines

for n_f = 3 and n_o = 4

n_f = 3   ml = -1, 0, 1

n₀= 4      ml = -2, -1, 0, 1, 2

Only transitions with  Δm_l = ±1 are allowed, so there are only two transitions plus the central transition (Δm_l = 0), so there are only 3 spectral lines.

In summary, due to the selection rule of spherical harmonics, the greatest number of lines in the Zeeman effect without spin is three lines.

3 0
3 years ago
A one-piece cylinder has a core section protruding from the larger drum and is free to rotate around its central axis. A rope wr
Sunny_sXe [5.5K]

Answer:

Explanation:

Torque created by force 3.34N

= 3.34 x 1.39 = 4.64 N.m

This torque is acting in clockwise direction .

Torque created by force 8.52 N

8.52 x .48

= 4.09 N.m

The force of 8.52 N is acting downward . It may turn the cylinder in clockwise or anticlockwise direction . So we shall consider both the possibilities.

If it rotates the cylinder in clockwise direction

Total torque = 4.64 + 4.09

= 8.73 Nm

If it rotates the cylinder in anticlockwise direction

Total torque = 4.64 - 4.09

= .55 Nm

Net torque will be in clockwise direction.

5 0
3 years ago
The latent heat of vaporization for water at room temperature is 2430 J/g.
alukav5142 [94]

Answer:

1)   kinectic energy=7.26*10^-^2^0J

2)  V= 2.0m/s

3)  T=3.5*10^3K

4)  The Molecules do not burn because of the presences of hydrogen bond in place

Explanation:

From the question we are told that

latent heat of vaporization for water at room temperature is 2430 J/g.

1)Generally in determining the molar mass of water evaporated we have that

-One mole (6.02 x 10. 23 molecules)

-Molar mass of water is 18.02 g/mol

Mathematically the mass of water is give as

   

  M=\frac{18.02}{6.02*10^-^2^6}

  M=3*10^-^2^3g

Therefore

  kinectic energy=2430J/g*3*10^-^2^3g

 kinectic energy=7.26*10^-^2^0J

b)Generally the evaporation speed V is given asV= \sqrt{\frac{K.E*2}{m} }

Mathematically derived from the equation

\frac{1}{2} mv^2 =K.E

To Give

V= \sqrt{\frac{K.E*2}{m} }

V= \sqrt{\frac{7.26*10^-^2^0J*2}{3*10^-^2^3g} }

V= 2.0m/s

c)Generally the equation for velocity   Vrms=\sqrt{\frac{3RT}{M} }

Therefore

Effective temperature T is given by

      T=\frac{\sqrt{v}*m}{R}

where

     T=\frac{\sqrt{2.0m/s}*6.02*10^-^2^6}{0.082057 L atm mol-1K-1}

     T=3.5*10^3K

4) The Molecules do not burn because of the presences of hydrogen bond in place

3 0
3 years ago
If Vx = 7.00 units and Vy = -7.60 units, determine the magnitude of V⃗ .
Juliette [100K]

|V| = 10.33 units and the direction θ = -47.35° or 312.65°.

Given the x and y components of a vector, we can calculate the magnitude and direction from these components.

Applying the Pythagorean theorem we have that the magnitude of the vector is:

|V| = \sqrt{Vx^{2}+Vy^{2}  }

|V| = \sqrt{(7.00units)^{2}+(-7.60units)^{2}} = \sqrt{106units^{2}} = 10.33units

The expression for the direction of a vector comes from the definition of the tangent of an angle:

tan θ = \frac{Vy}{Vx} ------>  θ = arc tan \frac{Vy}{Vx}

θ = arc tan \frac{-7.60units}{7.00units}

θ = -47.35° or 312.65°

6 0
3 years ago
Other questions:
  • A 150-if object takes 1.5 minutes to travel s 2,500-meter straight path. It begins the trip traveling 120 m/s and decelerates to
    5·1 answer
  • _mg(oh)2 + _HBr _mgBr2 + _HOH
    12·1 answer
  • Can someone tell me how to get the answers for 11.a) and b)
    11·1 answer
  • Consider a model of a hydrogen atom in which an electron is in a circular orbit of radius r = 5.92×10−11 m around a stationary p
    10·1 answer
  • A 1,700kg car is being used to give a 1,400kg car a push start by exerting a force of 140N the impulse on the smaller car during
    8·1 answer
  • A repeating disturbance that transfers energy through matter or space is called a _____.
    9·2 answers
  • If a storm is 7.5 kilometers away, how much time is expected between observations of lightning and thunder?
    5·2 answers
  • How does the size of a wind turbine affect its energy output?
    10·1 answer
  • Describe how you would draw a diagram that shows the electric field between two particles that
    13·2 answers
  • Help asap!
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!