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
mart [117]
3 years ago
15

g Radiation of an unknown wavelength is used in a photoelectric effect experiment on a sodium surface. The maximum kinetic energ

y of the observed electrons is 0.7 eV. What is the wavelength of the light
Physics
1 answer:
Andreas93 [3]3 years ago
4 0

Answer:

λ = 4.1638 10⁻⁷ m

Explanation:

The photoelectric effect was explained by Einstein assuming that the radiation acts like particles and the equation that describes the process is

           K = h f -Ф

where K is the kinetic energy of the emitted electrons, hf  the energy of the photons according to Planck's equation and Ф the work function of the material

In this case they give us the kinetic energy of the electrons

         K = 0.7 eV

The sodium work function is tabulated Ф = 2.28 eV

Let's find the frequency of the photons

            f = (K + Ф) / h

Planck's constant is

          h = 6.626 10⁻³⁴ J s (1 eV / 1.6 10⁻¹⁹ J) = 4.136 10⁻¹⁵ eV s

            f = (0.7 + 2.28) / 4.136 10⁻¹⁵

            f = 7.2050 10¹⁴ Hz

let's find the wavelength using the relationship between speed and frequency and wavelength

            c = λ f

            λ = c / f

            λ = 3 10⁸ / 7.205 10¹⁴

            λ = 4.1638 10⁻⁷ m

You might be interested in
With regard to pneumatic mechanical devices which afford protection against the formation of ice, which of the following stateme
Andreyy89

Answer:

the answer is The pneumatic mechanical device can only be used as a de-icing device.

Explanation:

An ice protection system prevents the formation of ice, or enables the aircraft to shed the ice before it can grow to a dangerous thickness. Ice protection systems are designed to keep atmospheric ice from accumulating on aircraft surfaces such as wings, propellers and engine intakes.

The pneumatic mechanical device is the Pneumatic deicing boots which was invented by the Goodrich Corporation in 1923. The pneumatic boot is usually made of layers of rubber, with one or more air chambers between the layers.

Any design which utilizes either a mechanical means of breaking the bond of ice to the surface, or which operates on a periodic cycle, is necessarily a de-ice system.

4 0
3 years ago
Was the Big Bang a loud explosion? Why?
Sholpan [36]

Answer:

bc it was a universal explosion and It started the future

Explanation:

FACTS

6 0
3 years ago
Read 2 more answers
A capacitor is connected across an ac source. Suppose the frequency of the source is doubled. What happens to the capacitive rea
fgiga [73]

The capacitive reactance is reduced by a factor of 2.

<h3>Calculation:</h3>

We know the capacitive reactance is given as,

Xc = \frac{1}{2\pi fC}

where,

Xc\\ = capacitive reactance

f = frequency

C = capacitance

It is given that frequency is doubled, i.e.,

f' = 2f

To find,

Xc =?

Xc' = \frac{1}{2\pi f'C}

      = \frac{1}{2\pi 2f C}

      = \frac{1}{2} (\frac{1}{2\pi fC} )\\

Xc' = \frac{1}{2} Xc

Therefore, the capacitive reactance is reduced by a factor of 2.

I understand the question you are looking for is this:

A capacitor is connected across an AC source. Suppose the frequency of the source is doubled. What happens to the capacitive reactant of the inductor?

  1. The capacitive reactance is doubled.
  2. The capacitive reactance is traduced by a factor of 4.
  3. The capacitive reactance remains constant.
  4. The capacitive reactance is quadrupled.
  5. The capacitive reactance is reduced by a factor of 2.

Learn more about capacitive reactance here:

brainly.com/question/23427243

#SPJ4

3 0
1 year ago
A particle moves horizontally in uniform circular motion, over a horizontal xy plane. At one instant, it moves through the point
seropon [69]

since centripetal acceleration is always towards the center of the circle

so at the given position where speed and acceleration is given the center coordinate will be towards the center of circle

also we know that

a_c = \frac{v^2}{r}

11.6 = \frac{2.5^2}{R}

R = 0.54 m

so the coordinates of the center will be

(x, y) = (3.20 , (3.5 + 0.54))

(x, y) = (3.20, 4.04)

so the coordinate is (3.20 m, 4.04 m)

6 0
3 years ago
PLZZZ HELP 100 POINTS WILL MARK BRAINELST
Kitty [74]

Explanation:

Crust...molten

a. Oceanic, iron

b. Continental, silicates

c. less

3. Mantle, Denser

a. Lithosphere

b. Asthenosphere

4. Core

a. elements, rocks

b. liquid, magnetic

(I guess the liquid should come after the is)

Couldn't answer all but wanted to help

3 0
3 years ago
Read 2 more answers
Other questions:
  • What type of properties would a scientist need to know to correctly place in new element into a group?
    8·1 answer
  • The smallest unit of a compound is called a ___________.
    5·1 answer
  • What information is needed to determine the orientation of an orbital?
    6·1 answer
  • A particle (mass = 4.0 g, charge = 80 mC) moves in a region of space where the electric field is uniform and is given by Ex = -2
    11·1 answer
  • An object began moving at the starting point (0,0) on the graph. The average speed of the object for the entire trip of 5.0 hour
    9·2 answers
  • A boy of mass, m weights 895 N. What is his mass, m?
    11·1 answer
  • What acceleration will you give to a 27.8 kg
    9·1 answer
  • if A and B are non zero vectors, is it possible for vector A×vector B and vector A.vector B both to be zero? Justify your answer
    9·1 answer
  • 2. The longest snake ever found was a python that was 10.0 m long. Sup-
    10·1 answer
  • Q C During a solar eclipse, the Moon, the Earth, and the Sun all lie on the same line, with the Moon between the Earth and the S
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!