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uysha [10]
2 years ago
8

A laser shines violet light with a frequency of 703 thz onto the metal with a threshold frequency of 295 thz, what is the kineti

c energy of the ejected electrons in ev? chegg
Physics
1 answer:
hram777 [196]2 years ago
3 0

The kinetic energy of the ejected electrons will be 2782.5 ×10⁻²² eV.

<h3>What is threshold frequency?</h3>

The threshold frequency of incoming radiation is the lowest frequency at which photoelectric emission or electron emission is impossible.

The threshold frequency is the light frequency that causes an electron to dislodge and emit from the metal's surface.

From the photoelectric effect, the equation obtained as;

\rm  hv=hv_0+KE\\\\ KE=h(v-v_0)\\\\ KE=6.625 \times 10^{-34}(702-282)Hz \\\\ KE= 6.625 \times 10^{-34}\times 420 \times 10^{12} \ Hz \\\\ KE=2782 .5 \times 10^{-22} \ eV

Hence,the kinetic energy of the ejected electrons will be 2782.5 ×10⁻²² eV.

To learn more about the threshold frequency, refer to the link;

brainly.com/question/2499414

#SPJ1

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Polarized light passes through a polarizer. If the electric vector of the polarized light is horizontal what, in terms of the in
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Answer:

The intensity of the light that passes through a polarizer is 0.55I₀.

Explanation:

The intensity of the light that passes through a polarizer can be found using Malus's law:  

I = I_{0}cos^{2}(\theta)

<u>Where</u>:

I: is the intensity of the light that passes through a polarizer

I₀: is the initial intensity

θ:  is the angle between the light's initial polarization direction and the axis of the polarizer = 42°  

I = I_{0}cos^{2}(\theta) = I_{0}cos^{2}(42) = 0.55*I_{0}

Therefore, the intensity of the light that passes through a polarizer is 0.55I₀.

I hope it helps you!  

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3 years ago
How can sand dunes be re-built?<br><br> PLEASE HELP ME
quester [9]
The basic steps are simple but careful planning is needed. Sand dune restoration should be designed to create a dune that matches the existing natural dune pattern in the area. You can help speed up nature's work by using sand fences and dune plants to collect sand more rapidly. Or in a different way, wind would bring more sand to create a dune. hope this helped, have an amazing day :)
7 0
4 years ago
When light shines through atomic hydrogen gas, it is seen that the gas absorbs light readily at a wavelength of 91.63 nm. What i
Artist 52 [7]

Answer:

D) 21

Explanation:

When gas absorbs light , electron at lower level jumps to higher level .

and the difference of energy of orbital is equal to energy of radiation absorbed.

Here energy absorbed is equivalent to wavelength of 91.63 nm

In terms of its energy in eV , its energy content is eual to

1243.5 / 91.63 = 13.57 eV. This represents the difference the energy of orbit .

Electron is lying in lowest or first level ie n = 1.

Energy of first level

= - 13.6 / 1² = - 13.6 eV.

Energy of n th level = - 13.6 / n². Let in this level electron has been excited

Difference of energy

= 13.6 - 13.6 / n² = 13.57 ( energy of absorbed radiation)

13.6 / n² = 13.6 - 13.57 = .03

n² = 13.6 / .03 = 453

n = 21 ( approx )

4 0
3 years ago
How long does it take venus to orbit the sun
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The answer is 225 days
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4 years ago
Read 2 more answers
An object is taken from an oven at 350o F and left to cool in a room at 70o F. If the temperature fell to 250o F in one hour, wh
Oksana_A [137]

Answer:

117.83° F

Explanation:

Using Newton's Law of Cooling which can be expressed as:

\dfrac{dT}{dt}= k(T-T_1)

The differential equation can be computed as:

\dfrac{dT}{dt}= k(T-70)

\dfrac{dT}{(T-70)}= kdt

\int \dfrac{dT}{(T-70)}= \int kdt

In|T-70| = kt +C

T- 70 = e^{kt+C} \\ \\ T = 70+e^{kt+C} \\ \\ T = 70 + C_1e^{kt}  --- (1)

where;

C_1 = e^C

At the initial condition, T(0)= 350

350 = 70 C_1^{k*0}

350 -70 = C_1

280 = C_1

replacing C_1= 280 into (1)

Hence, the differential equation becomes:

T(t) = 70 + 280 e^{kt}

when;

time (t) = 1 hour

T(1) = 250

Since;

250 = 70 + 280 e^{k*1}

180 = 280e^k \\ \\ \dfrac{180}{280}= e^k

k = In (\dfrac{180}{280})

k = -0.4418

Therefore;

T(t) = 70 + 280e^{(-0.4418)}t

After 4 hours, the temperature is:

T(t) = 70 + 280e^{(-0.4418)}4

T(4) = 117.83° F

7 0
3 years ago
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