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
Varvara68 [4.7K]
2 years ago
15

Violet light of wavelength 405 nm ejects electrons with a maximum kinetic energy of 0.890 eV from a certain metal. What is the b

inding energy (in electronvolts) of electrons to this metal
Physics
1 answer:
AleksandrR [38]2 years ago
4 0

Answer:

  Ф = 2.179 eV

Explanation:

This exercise has electrons ejected from a metal, which is why it is an exercise on the photoelectric effect, which is explained assuming the existence of energy quanta called photons that behave like particles.

            E = K + Ф

the energy of the photons is given by the Planck relation

            E = h f

we substitute

           h f = K + Ф

           Ф= hf - K

the speed of light is related to wavelength and frequency

            c = λ f

            f = c /λ

            Φ = \frac{hc}{\lambda } - K

let's reduce the energy to the SI system

            K = 0.890 eV (1.6 10⁻¹⁹ J / 1eV) = 1.424 10⁻¹⁹ J

calculate

           Ф = 6.63 10⁻³⁴ 3 10⁸/405 10⁻⁹  -1.424 10⁻¹⁹

           Ф = 4.911 10⁻¹⁹ - 1.424 10⁻¹⁹

           Ф = 3.4571 10⁻¹⁹ J

         

we reduce to eV

           Ф = 3.4871 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)

           Ф = 2.179 eV

You might be interested in
Hi, Solve for λ<br> E=hc/λ
Paul [167]

Answer:

λ=hc/E

Explanation:

E=hc/λ

Eλ=hc

λ=hc/E

4 0
3 years ago
you push a sled of mass 15 kg across the snow with a force of 180 N for a distance of 2.5 m. There is no friction. if the sled s
Oxana [17]
<span>7.7 m/s First, determine the acceleration you subject the sled to. You have a mass of 15 kg being subjected to a force of 180 N, so 180 N / 15 kg = 180 (kg m)/s^2 / 15 kg = 12 m/s^2 Now determine how long you pushed it. For constant acceleration the equation is d = 0.5 A T^2 Substitute the known values getting, 2.5 m = 0.5 12 m/s^2 T^2 2.5 m = 6 m/s^2 T^2 Solve for T 2.5 m = 6 m/s^2 T^2 0.41667 s^2 = T^2 0.645497224 s = T Now to get the velocity, multiply the time by the acceleration, giving 0.645497224 s * 12 m/s^2 = 7.745966692 m/s After rounding to 2 significant figures, you get 7.7 m/s</span>
5 0
3 years ago
A string under a tension of 50.4 N is used to whirl a rock in a horizontal circle of radius 2.51 m at a speed of 21.1 m/s. The s
Leokris [45]

Answer:

619.8 N

Explanation:

The tension in the string provides the centripetal force that keeps the rock in circular motion, so we can write:

T=m\frac{v^2}{r}

where

T is the tension

m is the mass of the rock

v is the speed

r is the radius of the circular path

At the beginning,

T = 50.4 N

v = 21.1 m/s

r = 2.51 m

So we can use the equation to find the mass of the rock:

m=\frac{Tr}{v^2}=\frac{(50.4)(2.51)}{21.1^2}=0.284 kg

Later, the radius of the string is decreased to

r' = 1.22 m

While the speed is increased to

v' = 51.6 m/s

Substituting these new data into the equation, we find the tension at which the string breaks:

T'=m\frac{v'^2}{r'}=(0.284)\frac{(51.6)^2}{1.22}=619.8 N

5 0
3 years ago
A 10 m long clothesline is strung so that it is perfectly horizontal. when a shirt is hung in the exact center the line sags to
Leto [7]

Answer:

x = 0.0873 m

Explanation:

given,

length of clothesline = 10 m

the line sags to create an angle that is 1 degree below the horizontal on each end.

As mass is hang at the center the angle made let the deflection be 'x'

as the shirt is hang at the center distance will be equal to 5 m.

now

tan \theta = \dfrac{d_e}{d}

tan \theta = \dfrac{x}{5}

tan 1^0 = \dfrac{W}{5}

W = 5 \times 0.0175

x = 0.0873 m

Hence, the cloth line will be x = 0.0873 m from the original length of the clothesline.

3 0
3 years ago
What are some everyday products we use made from refined metal or ore
FinnZ [79.3K]

Answer:

Hand tools.

Bolts, nuts, and screws.

Cans.

Cutlery.

Pipes and pipe fittings.

Metal windows and doors.

Equipment attachments.

Car parts.

Explanation:

4 0
3 years ago
Other questions:
  • A generator's maximum output is 220 V. What is the rms potential difference?
    15·1 answer
  • ( Science ) If the sun is far away then why does it look like we get higher than it when we lift a camera high in the sky?
    15·1 answer
  • A jet airplane lands with a speed of 120 mph. It has 1800 ft of runway after touch- down to reduce its speed to 30 mph. Compute
    15·1 answer
  • What are the potential obstacles preventing you from completing your exercises as scheduled? How can you overcome those obstacle
    9·1 answer
  • 10 points and brainliest to correct answer plz
    6·1 answer
  • When scientists want to determine the actual age of a fossil, they use_____________
    10·1 answer
  • Which of the following is a pure substance?
    10·2 answers
  • !!! HELP!!! HELL GELP HELP HELP
    8·2 answers
  • A step down transformer has a primary coil consisting of 700 tons and a secondary coil consisting of 300 times. What is the pote
    13·1 answer
  • An object is projected horizontally at 14.1 m/s from the top of a 195.0 meter cliff.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!