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
Julli [10]
3 years ago
12

The work function for tungsten metal is 4.52eV a. What is the cutoff (threshold) wavelength for tungsten? b. What is the maximum

kinetic energy of the electrons when radiation of wavelength 198nm is used? c. It is observed that the electrons may be prohibited from reaching the anode by applying a stopping potential. What is the stopping potential in the case when radiation of wavelength 198nm is used?
Physics
1 answer:
Tanya [424]3 years ago
5 0

Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V

Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:

h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.

In order to calculate the cutoff wavelength we have to consider that Ek=0

in this case  h*ν=W

(h*c)/λ=4.52 eV

λ= (h*c)/4.52 eV

λ= (1240 eV*nm)/(4.52 eV)=274.34 nm

From this h*ν = Ek+W;  we can calculate the kinetic energy for a radiation wavelength of 198 nm

then we have

(h*c)/(λ)-W= Ek

Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV

Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this  acts to slow down the ejected electrons from the catode.

You might be interested in
What are forces that two objects apply on each other
liq [111]
Answer: Whenever two objects are touching, they usually exert forces on each other. The force of gravity, on the other hand, is an example of a force that exists between objects without them having to be in contact. Objects with mass exert forces on each other via the force of gravity.

HOPE IT HELPED:) HAVE A NICE DAY
3 0
3 years ago
Consider the interference pattern produced by two parallel slits of width a and separation d, in which d = 3a. The slits are ill
laila [671]

Answer:

a)   m =1  θ = sin⁻¹  λ  / d,  m = 2        θ = sin⁻¹ ( λ  / 2d) ,   c)     m = 3

Explanation:

a) In the interference phenomenon the maxima are given by the expression

         d sin θ = m λ

the maximum for m = 1 is at the angle

          θ = sin⁻¹  λ  / d

the second maximum m = 2

          θ = sin⁻¹ ( λ  / 2d)

the third maximum m = 3

        θ = sin⁻¹ ( λ  / 3d)

the fourth maximum m = 4

       θ = sin⁻¹ ( λ  / 4d)

b) If we take into account the effect of diffraction, the intensity of the maximums is modulated by the envelope of the diffraction of each slit.

       I = I₀ cos² (Ф) (sin x / x)²

       Ф = π d sin θ /λ

       x = pi a sin θ /λ

where a is the width of the slits

with the values ​​of part a are introduced in the expression and we can calculate intensity of each maximum

c) The interference phenomenon gives us maximums of equal intensity and is modulated by the diffraction phenomenon that presents a minimum, when the interference reaches this minimum and is no longer present

maximum interference       d sin θ = m λ

first diffraction minimum    a sin θ = λ

we divide the two expressions

                       d / a = m

In our case

                   3a / a = m

                    m = 3

order three is no longer visible

7 0
3 years ago
In a nuclear reaction, which of the following must be conserved?
AfilCa [17]

Answer:

c

Explanation:

7 0
3 years ago
Read 2 more answers
In water what happens to a base?
Ratling [72]
Your answer would be B. It forms hydrogen ions (H+)
4 0
3 years ago
Read 2 more answers
Sylvia and Jadon now want to work a problem. Imagine a puck of mass 0.5 kg moving in a circular simulation. Suppose that the ten
leva [86]

Answer:

Tangential speed, v = 2.64 m/s

Explanation:

Given that,

Mass of the puck, m = 0.5 kg

Tension acting in the string, T = 3.5 N

Radius of the circular path, r = 1 m

To find,

The tangential speed of the puck.

Solution,

The centripetal force acting in the string is balanced by the tangential speed of the puck. The expression for the centripetal force is given by :

F=\dfrac{mv^2}{r}

v=\sqrt{\dfrac{Fr}{m}}

v=\sqrt{\dfrac{3.5\ N\times 1\ m}{0.5\ kg}}

v = 2.64 m/s

Therefore, the tangential speed of the puck is 2.64 m/s.

3 0
3 years ago
Other questions:
  • A snowball is launched horizontally from the top of a building at v = 16.9 m/s. If it lands d = 44 meters from the bottom, how h
    8·1 answer
  • Why do slippery fluids such as oil reduce sliding friction
    14·1 answer
  • Pushing a rock from a hill top is called
    7·1 answer
  • A 19 nC charge is moved in a uniform electric field. The electric field does 5.3 μJ of work as the charge moves from point A to
    7·1 answer
  • A sinusoidal wave has period 0.20 s and wavelength 2.0 m. What is the wave speed?
    9·1 answer
  • A(n) _____ particle is a particle that contains two protons, two neutrons, and has a 2 charge.
    14·2 answers
  • Any fracture or system of fractures along which Earth moves is known as a
    15·1 answer
  • A common, though incorrect, statement is, "The Moon orbits the Earth." That creates an image of the Moon?s orbit that looks like
    7·1 answer
  • The lift took 5 seconds to arrive at the second floor. What was the power of lift?
    15·2 answers
  • Two waves travel at the same speed, but one has a larger period. What other parameter/s would be affected by this? (Check all th
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!