Lithium was one of the metals studied by the American physicist Robert Millikan in his research on the photoelectric effect. When illuminated with blue light of frequency 6.64 x 10" Hz, the photoelectrons ejected from a lithium surface have a maximum kinetic energy of 0.332 eV. What is the threshold frequency for lithium? For this problem, let the value of Planck's constant, h, be 6.63 x 10J's

Answers

Answer 1

Answer:

 f = 7.9487 10¹³ Hz

Explanation:

The photoelectric effect was correctly explained by Einstein assuming that the radiation is composed of photons, which behave like particles.

           hf = K + Ф

It indicates the frequency and the kinetic energy, let's look for the work function

          Ф = hf - K

let's reduce the magnitudes to the SI system

          K = 0.332 eV (1.6 10⁻¹⁹ J / 1 eV) = 0.5312 10⁻⁻¹⁹ J

let's calculate

          Ф = 6.63 10⁻⁻³⁴  6.64 10¹¹ - 0.5312 10⁻¹⁹

          Ф = 4.40 10⁻²² - 0.5312 10⁻¹⁹

          Ф = 5.27 10⁻²⁰ J

for the minimum frequency that produces photoelectrons, the kinetic energy is zero

           hf = Ф  

           f = Ф / h

           f = 5.27 10⁻²⁰ / 6.63 10⁻³⁴

           f = 7.9487 10¹³ Hz


Related Questions

What is the female counterpart of sperm?
the vagina
the ovum
the zygote
the epididymus

Answers

Answer:

The zygote

Explanation:

The sperm is what fertilized the egg and the zygote is basically part of the female egg cell.

Hope this Helps!Hope this Helps!:)

Answer:

the answer is the ovum on edge

Explanation:

Water enters a shower head
through a pipe of radius 0.0112 m
at 3.75 m/s. It flows through 25
small holes, each of radius
0.001200 m. At what speed does
water come out of the shower
head? (Don't forget, there are 25
holes, not 1.)
(Unit = m/s)

Answers

Answer:

13.1

Explanation:

thats what i put in for acellus and its right

Which is the correct formula for calculating speed?
A. speed - distance - time
B. speed = distange + time
C. speed = distance - time
D. speed = distance - acceleration

Answers

Answer:

speed=distance/time

Explanation:

its distance over time like division


How did our Sun form? *

A cloud of stellar dust from part of a Nebula collapsed causing hydrogen atoms to
fuse together.

Many smaller stars became fused together by gravity

It broke off from a larger star in the universe.

Two gas giants from another solar system became fused together by gravity.

Answers

Answer: A cloud of stellar dust from part of a Nebula collapsed causing hydrogen atoms to fuse together

Explanation:

sinat
Accelerationa
2 2.84
7 34
TABLE
in Elination
t2 t3 T2 2
1=0.04
2.29 1.25 1.28 1.271.61
2 460 = 0.00 4.59 1.16 1.081.12 1-25
3 so = 0.12 6.89 0.88
097 0.53
4. = 0.16 9.210.8
9.21 0.850.796. 82/0.67
(So
0.72 0.77 0.75 l 0-56/
0.28
49. al
27. 49
13 11%.
41. 2L
= 0.2 11.54​

Answers

Answer:

so you have a question

Explanation:

either way,you have a nice day

Calculate the magnitude of the electric field at one corner of a square 2.42 m on a side if the other three corners are occupied by 2.75×10−6 C charges.

Answers

Answer:

loloeuhsh

Explanation:

shwvwgnwajejjeisus

1.A body of mass 10kg falling freely was found to be falling at a rat of 20m/s what force will stop the body in 2second?​

Answers

Answer:

50N

Explanation:

force it is falling with can be found by mass into acceleration and then devide by half to find force that could stop it in 2 sec


A student pushes a 12 N book to the
right with a force of 10 N. The book
experiences a frictional force of 3 N.

Answers

Answer:

Explanation:

My name is Jeff

A 45.7 kg woman starts from rest at the bottom of a flight of stairs that has
a total height of 2.54 meters. She reaches the top of the stairs
in 5.00 seconds. How much power does she generate if she is moving at
2.63 m/s at the top of the stairs? Use g = 9.8 m/s2, and only include 3
numbers in your answer.

Answers

Answer:

The power generated by the woman is 259 W

Explanation:

Given;

mass of the woman, m = 45.7 kg

initial velocity of the woman, u = 0

total height ascended by the woman, h = 2.54 m

time of the woman's motion, t = 5.0 s

final velocity of the woman, v = 2.63 m/s

acceleration due to gravity, g =  9.8 m/s²

The potential energy of the woman due to the height she ascended;

P.E = mgh

P.E = 45.7 x 9.8 x 2.54

P.E = 1137.564 J

The kinetic energy of the woman due to her final velocity;

K.E = ¹/₂mv²

K.E = ¹/₂ x 45.7 x (2.63)²

K.E = 158.051 J

The total mechanical energy of the woman at the top of the stairs;

M.E = P.E + K.E

M.E = 1137.564 J  +  158.051 J

M.E = 1295.615 J

The power generated by the woman;

Power = Energy/time

Power = 1295.615 J / 5 s

Power = 259.123 W

Power = 259 W

If I have an object with a 6.0 µC charge , and another with a -2.0 µC charge, when they touch how do I find the new charges

Answers

When charged objects touch, you can assume that the charges move between the objects, so that the total amount of charge doesn't change but it splits equally between the two objects.

-- like two water tanks standing next to each other, with a different amount of water in each one.  When you connect a pipe between their bottoms, some water flows across until the LEVEL of water is the same in both tanks.

-- like one hard full balloon and one soft mooshy balloon.  When you connect them together, some air flows from the hard balloon into the soft balloon, until the pressure of air is the same in both balloons.  

The total amount of charge on your two objects is (+6.0 μC  -  2.0 μC).  That's +4.0 μC  .

When they touch, charges move around until the charge is the same on both objects . . . +2 μC.

An ideal horizontal spring-mass system is set into motion. At an instant when the mass passes through its equilibrium position: The potential energy in the spring is at its _____. The kinetic energy of the mass is at its ______. The magnitude of net force acting on the mass is at its ______.

Answers

Answer:

the potential energy is zero, and the kinetic energy must be maximum

    F = 0

Explanation:

In this exercise you are asked to complete the sentences of a simple harmonic movement of a mass-spring system.

In this system mechanical energy is conserved

at the most extreme point the carousel potential energy is

          K_e = ½ k x²

the kinetic energy is zero for that stopped.

At the equilibrium point

the spring elongation is x = 0 so the potential energy is zero

and the kinetic energy must be maximum since total energy of the system is conserved

the spring force is

             F =- k x

as in the equilibrium position x = 0 this implies that the force is also zero

             F = 0

In this exercise we have to use the knowledge of force to calculate the energy of a spring, in this way we find that:

The potential energy in the spring is at its [tex]K_e = 1/2 k x^2[/tex]. The kinetic energy of the mass is at its zero . The magnitude of net force acting on the mass is at its Zero.

In this system mechanical energy is conserved,  at the most extreme point the carousel potential energy is:

       [tex]K_e = 1/2 k x^2[/tex]

The kinetic energy is zero for that stopped or when at the equilibrium point, so:

the spring elongation is x = 0 so the potential energy is zero the kinetic energy must be maximum since total energy of the system is conserved

the spring force is:

          [tex]F =- k x\\F=0[/tex]

See more about force at brainly.com/question/26115859

12. A glass plate 1 cm thick, of refractive index 1.50, is placed
between a point source of light of wave length 6000 Å and a
screen. The distance from the source to the screen is 4 cm.
How many waves are there between the source and the
screen?

Answers

Answer:

7

Explanation:

The light travels a total of 4 cm to the screen, of that, 3 cm is in air and 1 cm is in the glass plate.

The total number of wavelengths of light between the source and screen is just the number of wavelengths in air plus the number in the glass.

To determine the number of wavelengths in air, divide the thickness of air (3 cm) by the wavelength of the light (6000 Angstroms), converting units as needed.

The refractive index of the glass is 1.5. That means that the velocity of propagation of the light in the glass is 2/3 of what it is in air, and so the wavelength of the light in glass is 2/3 of what it is in air. So, divide the thickness of glass (1 cm) by the wavelength of the light in glass (6000 * 2/3).

Add the two values for the final answer

What is it called when a Rock forms due to heat and pressure in the earth?

Answers

It is called Metamorphic rocks!!

1. An atom that loses electrons has a ________________________ charge and an atom that gains
electrons has a ___________________________ charge.
Charged atoms are called ___________________.
2. What is an insulator? Give 4 examples.
3. What is a conductor? Give an example.
4. How can we move electrons from one place to another? What actually causes the electrons to
move?
5. Static electricity is ______________________________________________________________________
_______________________________________________________________________________________
6. Explain the attraction and repulsion of charges.
7. Why does a balloon stick to the wall?
8. Why does your hair stand up when you take off your hat?
9. Why do you get a shock when you walk across a carpet?
10. When is static electricity most noticeable and why?
11. State the Principle of Conservation of Charge.

12. The invisible electric force field around charged objects depends on __________________________,
__________________________, and _____________________________.
13. What is the relationship between the charges and the field strength?
What is the relationship between the field strength and the distance between the charges?
1. What is DC?
What is AC?
2. Name 3 ways to get DC.
3. What is an electrical circuit?
4. What is voltage?
What is current?
What is resistance?
What causes heat and light in a wire?
COPY THE TABLE comparing water in a hose-DC-units
5. Which electricity do we use in our homes?
CLICK ON ALTERNATING CURRENT
1. Explain AC.
2. Who invented the light bulb?
3. Who really invented AC?
4. Who discovered the advantages of AC over DC?
5. How is AC made?
6. What is the main advantage of AC over DC?

Answers

I’ll start you off

1. Positive, negative, ions

Answer a few yourself and I’ll come back and help some more.

What is the mass of an object if a force of 17 N causes it to accelerate at 1.5 m/s/s?

Answers

Answer:

11.34 i think

Explanation:

Does gravity increase or decrease with greater mass???

Answers

Answer:

Increase

As the mass of either object increases, the force of gravitational attraction between them also increases.

Explanation:

The gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force.

As the mass of either object increases, the force of gravitational attraction between them also increases.

Answered by none other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO

HOPE THIS HELPED!!!

A.) A gemstone of mass 1.8 kg compresses a scale's spring by 2.6 cm.
Determine the spring constant.

B.) How much would the spring in the previous question compress if a 5.2 kg mass was placed on the scale?

Answers

Explanation:

Given that,

Mass, m = 1.8 kg

Compression, x = 2.6 cm

We know that,

Force on spring = weight

So,

[tex]mg=kx[/tex]

Where

k is spring constant

[tex]k=\dfrac{mg}{x}\\\\k=\dfrac{1.8\times 9.8}{2.6\times 10^{-2}}\\\\k=678.46\ N/m[/tex]

(2) If m = 5.2 kg

[tex]x=\dfrac{mg}{k}\\\\x=\dfrac{1.8\times 9.8}{678.46}\\\\x=2.6 \ cm[/tex]

Hence, this is the required solution.

When a mass is suspended from a spring the latter extends over a distance of 10cm. What will be the period of oscillations of the same system if it is placed horizontal on a frictionless surface​

Answers

Answer:

0.64 s

Explanation:

It's period of oscillation (T) can be determined by,

T = 2[tex]\pi[/tex][tex]\sqrt{\frac{l}{g} }[/tex]

Where l is the length (extension on the spring), and g the acceleration due to gravity.

But,

l = 10 cm = 0.1 m

g = 9.8 m/[tex]s^{2}[/tex]

Thus,

T = 2 x [tex]\frac{22}{7}[/tex] [tex]\sqrt{\frac{0.1}{9.8} }[/tex]

  = 0.6350

T = 0.64 s

The period of oscillation would be 0.64 s.

PLEASE HELP ASAP!
A machine has an efficiency of 70%. What happens to the other 30% of the work?

Answers

Answer:

The other 30% is lost from friction.

Explanation:

       friction 30% ---> |O| <------ 70% work

A machine has an efficiency of 70%, and the remaining 30% of the input work is lost as waste energy or dissipated in the form of heat, noise, or vibration, which cannot be harnessed to do any useful work.

What is work done by machine?

In any machine, the total work input is equal to the total work output plus any work that is lost or dissipated due to various factors such as friction, heat transfer, etc., so, for example, if a machine receives 100 units of energy as input, only 70 units of energy are converted into useful output work, and the remaining 30 units of energy are lost as waste energy.

Hence, the remaining 30% of the input work is lost as waste energy or dissipated in the form of heat, noise, or vibration, which cannot be harnessed to do any useful work.

Learn more about the work by machine here.

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3. An airplane is flying at 10 km altitude in the standard atmosphere. The internal pressure of the aircraft interior is 100 kPa. Estimate the outward force on the window. The window is flat and has an elliptical shape with lengths of 300 mm along the major axis and 200 mm along the minor axis.

Answers

Answer:

The correct response will be "13.755 kN".

Explanation:

According to the question,

The given values are:

a = 300 mm

i.e.,

  = 0.3 cm

b = 200 mm

i.e.,

  = 0.2 dm

Internal pressure,

[tex]P_{in}=100[/tex]

Now,

The area of the elliptical shape window will be:

⇒  [tex]A = \pi ab[/tex]

On substituting the values, we get

⇒      [tex]=3.14\times 0.300\times 0.200[/tex]

⇒      [tex]=0.1885 \ m^2[/tex]

By using the table,

At 10 km, the atmospheric pressure will be

⇒  [tex]p_o=27.03 \ kPa[/tex]

Now,

The outward force will be:

⇒  [tex]F_{net}=p_{in}A-p_{0}A[/tex]

⇒          [tex]=(p_{in}-p_{0})A[/tex]

⇒          [tex]=(100-27.03)\times (0.1885)[/tex]

⇒          [tex]=13.755 \ kN[/tex]

What do microwaves have In common with light waves?

Answers

Answer:

Both are electromagnetic waves

Explanation:

Hope this helped!!

What is The substance that dissolves the solute.

Answers

Answer:

Explanation:

Do you mean the solvent? If this is off the mark, let me know in a comment.

The solvent is something that the solute is (usually) soluble in.

PLEASE HELP

name 4 fundamentally different options for cooking a chicken​

Answers

Answer:

roasting,

broiling,

pan-broiling,

pan-frying,

grilling.

Explanation:

good luck

Answer:

Explanation:

1. Stir frying

2. Pan frying

3. Grilling /BBQ

4. Baking/roasting

g A projectile of mass 3 kg is launched horizontally from an initial height 3 m with an initial velocity 10 m/s. This velocity in the x direction is preserved when you ignore air resistance. The projectile still accelerates in the vertical y direction toward the ground, but this is exactly the energy lost from potential energy. Energy is conserved as long as you use the total mechanical energy equation. What is the final kinetic energy as the projectile just reaches the ground

Answers

Answer:

The kinetic energy at ground will be "238.2 J".

Explanation:

The given values are:

mass,

m = 3 kg

Initial height,

h = 3 m

Initial velocity,

v = 10 m/s

By using the conservation of energy at points A and B,

⇒  [tex]E_A=E_B[/tex]

⇒  [tex]mgh+\frac{1}{2}mv^2=k_B[/tex]

On substituting the values, we get

⇒  [tex]3\times 9.8\times 3+\frac{1}{2}\times 3\times (10)^2=k_B[/tex]

⇒             [tex]88.2+0.5\times 3\times 100=k_B[/tex]

⇒                            [tex]88.2+150=k_B[/tex]

⇒                                    [tex]238.2 =k_B[/tex]

explain why a diver at the bottom of the sea feels more pressure than one who is swimming on the surface of water​

Answers

As you go more further down the water the pressure increases. The deeper diver goes the more water will be above them. Meaning, they will experience more pressure than person who is swimming at the surface water.

Answer:

the deeper into the ocean you go, the more pressure is exerted on you

Explanation:

Suppose a proton ( = 1. 67×10^−27 kg) is confined to a box of width = 1. 00×10^−14 m (a typical nuclear radius).
1. What are the energies of the ground and the first excited states?
2. If the proton makes a transition from the first excited state to the ground state, what are the energy and the frequency of the emitted photon?

Answers

Answer:

22e837281949222324

Explanation:


Give the relationship between the number of valence electrons in an atom's
valence electron shell and the position of the element on the Periodic Table​

Answers

Answer:

they're reactions

Explanation:

The relationship between the valence electrons and position is: the number of valence electrons determines the position

What is valence electron?

This is the number of electrons in the outermost shell of an atom.

NOTE: The outermost shell is called valence shell

Position in Periodic table

This is where an element is located in the periodic table

Relationship between valence electrons and position

The position of an element in the periodic table is determined by the number of valence electrons.

For example

Sodium, Na (atomic number of 11) has the following electronic configuration

1st shell = 2 electrons2nd shell = 8 electrons 3rd (valence) shell = 1 electron

Since the valence electron is 1, thus, sodium is located in group 1 of the periodic table.

Thus, we can see that the position of an element in the periodic table is related to the valence electron(s) in the atomic shell of the element.

Learn more about valence electron:

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How do scientists know the continents were once closer than they are today? Explain your answer in 2-3 complete sentences.

Answers

Answer:

Continental drift describes one of the earliest ways geologists thought continents moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics. 

 

The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other. He called this movement continental drift. 

Determine the kinetic energy of a 2000 kg roller coaster car that is moving at the speed of 10 ms

Answers

Answer:

[tex]\boxed {\boxed {\sf 100,000 \ Joules}}[/tex]

Explanation:

Kinetic energy is energy due to motion. The formula is half the product of mass and velocity squared.

[tex]E_k= \frac{1}{2} mv^2[/tex]

The mass of the roller coaster car is 2000 kilograms and the car is moving 10 meters per second.

m= 2000 kg s= 10 m/s

Substitute these values into the formula.

[tex]E_k= \frac{1}{2} (2000 \ kg ) \times (10 \ m/s)^2[/tex]

Solve the exponent.

(10 m/s)²= 10 m/s * 10 m/s= 100 m²/s²

[tex]E_k= \frac{1}{2} (2000 \ kg ) \times (100 \ m^2/s^2)[/tex]

Multiply the first two numbers together.

[tex]E_k= 1000 \ kg \times (100 \ m^2/s^2)[/tex]

Multiply again.

[tex]E_k= 100,000 \ kg*m^2/s^2[/tex]

1 kilogram square meter per square second is equal to 1 Joule. Our answer of 100,000 kg*m²/s² is equal to 100,000 Joules.

[tex]E_k= 100,000 \ J[/tex]

The roller coaster car has 100,000 Joules of kinetic energy.

the speed of light in a certain medium is 0.6c. find critical angle , if the index of refraction is 1.67​

Answers

Answer:

[tex]\theta_c = 36.78^o[/tex]

Explanation:

The relationship between the refractive index and the critical angle is given as follows:

[tex]\eta = \frac{1}{Sin\ \theta_c} \\\\Sin\ \theta_c = \frac{1}{\eta}\\\\\theta_c = Sin^{-1}(\frac{1}{\eta} )[/tex]

where,

η = refractive index = 1.67

θc = critical angle =?

Therefore,

[tex]\theta_c = Sin^{-1}(\frac{1}{1.67} )[/tex]

[tex]\theta_c = 36.78^o[/tex]

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