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2 years ago

‏Explain how an electron emitted by the photoelectric effect can have kinetic energy less than threshold energy ?

Physics

1 answer:

xenn [34]2 years ago

4 0

Answer:

the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.

K = E - Ф

Explanation:

The photoelectric effect is the emission of electrons from the surface of a metal.

This was correctly explained by Einstein, in his explanation the energy of the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.

E = hf

E = K + Ф

K = E - Ф

The energy of the photons is given by the Planck relation E = hf and according to Einstein the number of joints must be added

E = n hf

Therefore, depending on the value of this energy, the emitted electrons can have energy from zero onwards.

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A toroidal solenoid has an inner radius of 12.0 cm and an outer radius of 15.0 cm . It carries a current of 1.50 A . Part A How

tensa zangetsu [6.8K]

Answer:

The number of turns is $N = 1750 \ turns$

Explanation:

From the question we are told that

The inner radius is $r_i = 12.0 \ cm = 0.12 \ m$

The outer radius is $r_o = 15.0 \ cm = 0.15 \ m$

The current it carries is $I = 1.50 \ A$

The magnetic field is $B = 3.75 mT = 3.75 *10^{-3} \ T$

The distance from the center is $d = 14.0 \ cm = 0.14 \ m$

Generally the number of turns is mathematically represented as

$N = \frac{2 * \pi * d * B}{ \mu_o * r_o }$

Generally $\mu_o$ is the permeability of free space with value

$\mu_o = 4\pi * 10^{-7} \ N/A^2$

$N = \frac{2 * 3.142 * 0.14 * 3.75 *10^{-3} }{ 4\pi * 10^{-7} * 0.15 }$

$N = 1750 \ turns$

5 0

2 years ago

Kyle is wondering what he is getting for his birthday. He decides to shake the box that contains his present. Kyle did not reali

stiks02 [169]

Answer: Asking questions

Explanation:

Scientists always start with their question before

Observing anything

8 0

2 years ago

When calculating the power bill, power companies use _____.

Dovator [93]

I think the correct answer from the choices listed above is option B. When calculating the power bill, power companies use kilowatt-hours. This unit is a derived unit of energy equal to 3.6 MJ. If energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt-hours is the product of the power in kilowatts and the time.

5 0

3 years ago

I need help with question 4 please

Yuki888 [10]

Answer:

V = 10 km / 1 hr = 10 km/hr

V = -10 j km / hr if one were to use i, j, k as unit vectors with the usual orientation

4 0

2 years ago

Dolphin echolocation is similar to ultrasound. Reflected sound waves

s344n2d4d5 [400]

Answer:

Waves with high frequencies have shorter wavelengths that work better than low frequency waves for successful echolocation.

Explanation:

To understand why high-frequency waves work better than low frequency waves for successful echolocation, first we have to understand the relation between frequency and wavelength.

The relation between frequency and wavelength is given by

λ = c/f

Where λ is wavelength, c is the speed of light and f is the frequency.

Since the speed of light is constant, the wavelength and frequency are inversely related.

So that means high frequency waves have shorter wavelengths, which is the very reason for the successful echolocation because waves having shorter wavelength are more likely to reach and hit the target and then reflect back to the dolphin to form an image of the object.

Thus, waves with high frequencies have shorter wavelengths that work better than low frequency waves for successful echolocation.

3 0

3 years ago