A trained eye in the dark for an extended period of time may pick up a light stimulus from a light source, at the lowest radiated power of 1,2*10* (- 17) W. Determine how many photons of light with a wavelength of 500nm fall on the retina of the eye every second

Answers

Answer 1

Answer:

    #_photons = 30 photons / s

Explanation:

Let's start by finding the energy of a photon of light, let's use the Planck relation

         E = h f

the speed of light is related to wavelength and frequency

         c = λ f

we substitute

         E = h c /λ

         E₀ = 6.63 10⁻³⁴ 3 10⁸/500 10⁻⁹

         E₀ = 3.978 10⁻¹⁹ J

now let's use a direct proportion rule. If the energy of a photon is Eo, how many fornes has an energy E = 1.2 10⁻¹⁷ J in a second

          #_photons = 1 photon   (E / Eo)

          #_photons = 1  1.2 10⁻¹⁷ /3.978 10⁻¹⁹

          #_photons = 3.0 10¹

          #_photons = 30 photons / s


Related Questions

1. A massive object can distort the light of more distant objects behind it through the phenomenon that we call ________. 2. ________ are defined as subatomic particles that have more mass than neutrinos but do not interact with light. 3. The _____________ of spiral galaxies provide strong evidence for the existence of dark matter. 4. Models show that the _________ of the universe is better-explained when we include the effects of dark matter along with the effects of luminous matter.

Answers

Answer:

1. Gravitational lensing.

2. Weakly interacting massive particles (WIMPs).

3. Rotation curves.

4. Large-scale structure.

Explanation:

In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.

Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.

Light wave can be defined as an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.

The following statements are matched to give the characteristics of matter with respect to light;

1. A massive object can distort the light of more distant objects behind it through the phenomenon that we call: gravitational lensing. The gravitational field distorts and magnifies light from a distant galaxy such as quasars.

2. Weakly interacting massive particles (WIMPs): are defined as subatomic particles that have more mass than neutrinos but do not interact with light.

3. The rotation curves of spiral galaxies provide strong evidence for the existence of dark matter.

4. Models show that the large-scale structure of the universe is better-explained when we include the effects of dark matter along with the effects of luminous matter.

The heat current across a certain cinductive material is H. If the cross-sectional area of the material is tripled and everything else remains the same, how is the heat current affected?

Answers

Answer:

Resistance is inversely proportional to the cross section area of the material, hence when cross sectional area is tripled, also resistance triples.

Since heat is caused due to resistance, also heat current triples.

The average mass of an adult American female is 75 kilograms. What is the weight of
the average female in pounds?

Answers

Answer:

with 75kg --> 165.35 pound(lb)

Explanation:

[tex] \frac{75}{0.45359237} [/tex]

The average weight is 165 pounds since 1 kilo is 2.2 lbs. 2.2*75=165

The inventor of the electric cell was:
O Coulomb
Franklin
o Gilbert
O Volta

Answers

Answer:

The inventor of the electric cell was:

Alessandro Volta (in other words, Volta)

Explanation:

Answer:

Volta

Hope this helped you!!

Brainliest plsss

Explanation:

Alessandro Volta, in full Conte Alessandro Giuseppe Antonio Anastasio Volta, (born February 18, 1745, Como, Lombardy [Italy]—died March 5, 1827, Como), Italian physicist whose invention of the electric battery provided the first source of continuous current

A balloon is rubbed against a student's hair and then touched to a
wall. The balloon sticks to the wall due to:
(a) magnetic forces between the particles of the balloon and the
particles of the wall
(b) electrostatic forces between the particles of the balloon and
the particles of the wall
(c) magnetic forces between the particles of the wall
(d) electrostatic forces between the particles of the balloon

Answers

Answer:

B. electrostatic forces between the particles of the balloon and the particles of the wall

B

Please help!


A string of length Lis clamped at each end. It CAN'T vibrate with a 1
equal to

Answers

Answer:

4L is the answer

Explanation:

What protects and supports body organs and provides a framework the muscles use to support movements,made up of bones and joints

Answers

Answer: Skeletal system

Explanation:

The skeletal system is a framework of the body. It comprises of connective tissues like bones, tendons, ligaments, and cartilage. All these connective tissues of the skeletal system connect with the muscular system of the body this helps in the locomotion of the body. The conjugation of the musculoskeletal system will also protect the internal organs of the body and will prevent the internal organs from injuries.

Answer:

the skeletal system

Explanation:

Because our skeleton is the framework of the body. :)

Every chemical compound is unique and different from the ____________________ it contains.
a.
molecules
c.
elements
b.
hydrogen
d.
gas

Answers

Answer:

C is your answer fam.

Explanation:

Calcula la cantidad de calor que hay que darle a 0,01 l de mercurio para que su temperatura pase de 10 ºC a 25 ºC. Datos: rho=13,6 g/cm3 ; Ar(Hg)=200,6; C=28,1 J/(mol∙K).

Answers

Respuesta:

286 J

Explicación:

Paso 1: Convertir 0,01 L de Hg a cm³

Usaremos los siguientes factores de conversion.

1 L = 1000 mL

1 mL = 1 cm³

0,01 L × 1000 mL/1 L × 1 cm³/1 mL = 10 cm³

Paso 2: Calcular la masa (m) correspondiente a 10 cm³ de Hg

La densidad de Hg es 13,6 g/cm³.

10 cm³ × 13,6 g/cm³ = 136 g

Paso 3: Calcular los moles(n) correspondientes a 136 g de Hg

La masa molar de Hg es 200,6 g/mol.

136 g × 1 mol/200,6 g = 0,678 mol

Paso 4: Calcular la cantidad de calor requerido (Q)

Usaremos la siguiente fórmula.

Q = c × n × (T₂ - T₁)

donde,

c: calor específico del Hg (28,1 J/mol.K = 28,1 J/mol.K)

T₂ y T₁: temperaturas final e inicial, respectivamente

Q = (28,1 J/mol.°C) × 0,678 mol × (25°C - 10 °C) = 286 J

In 1993, the gold reserves in the United States were about 8.490 × 106
kg. If all
that gold were made into a thick wire with a cross-sectional area of 1cm2
, its
total resistance would be about 6.60 × 102 Ω. If the same operation were
applied to the gold reserves of Germany, France, and Switzerland, the
resistances would be 2.40 × 102 Ω, 2.00 × 102 Ω, and 2.00 × 102 Ω,
respectively. Now consider all four resistors connected as shown in the circuit
diagram below. Find the equivalent resistance.

Answers

The equivalent resistance of the circuit is 65.98 Ω.

What is Resistor?

A resistor is an electrical component that limits or regulates the flow of electrical current in a circuit. It is designed to provide a specific amount of resistance to the flow of electrons, measured in ohms, and is typically made of a material that can resist the flow of electricity, such as carbon or metal. Resistors are used in a wide range of electronic devices and circuits, from simple LED flashers to complex computer systems.

To find the equivalent resistance of the circuit, we need to use the formula for resistors in parallel:

1/Req = 1/R1 + 1/R2 + 1/R3 + 1/R4

where Req is the equivalent resistance, and R1, R2, R3, and R4 are the resistances of the four resistors.

Substituting the given values, we get:

1/Req = 1/6.60 × 102 + 1/2.40 × 102 + 1/2.00 × 102 + 1/2.00 × 102

1/Req = 0.01515

Req = 65.98 Ω

Therefore, the equivalent resistance of the circuit is 65.98 Ω.

Learn more about Resistor from given link

https://brainly.com/question/17563681

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Brainliest for correct answer :)
An object travelling for 20 seconds initially travels at 10ms-1 and increases its speed to 40ms-1 what is its acceleration?

Answers

Answer:

Acceleration a =-1.75 m/s²

Explanation:

Given:

Initial speed u = 24 m/s

Final speed v = 10 m/s

Time taken t = 8 sec

Find:

Acceleration a

Computation:

a = (v-u)/t

a = (10-24)/8

a = -14 / 8

Acceleration a =-1.75 m/s²

Does earths Roation causes gravity?​

Answers

Answer:

he gravity of Earth, denoted by g, is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation )

describe the shape of a screw

Answers

Answer:

The shape of a screw is a cylindric shape that grows in diameter at the top. Along the cylindar portion, it has horizantal ridges that circulate around the screw.

Hope this helps, brainliest pls :D

Water molecules are made of slightly positively charged hydrogen atoms and slightly negatively charged oxygen
atoms. Which force keeps water molecules stuck to one another?

Answers

Answer:

Surface tension.

Explanation:

Water has this thing called surface tension, where the water, most of the time, is hard to split.

A few examples of surface tension in action:

If you spill some water, you can see that they seem to connect together as if they were magnetic.You can put around 20-30 drops of water on average on a penny. This shows that water has better surface tension than other liquids, like oil, that can the penny can only hold around 10-15.Lastly, water bugs (which are kind of like mosquitos) can actually stay on top of the water, because they do not break the surface tension of it.

Hope this helps you!

How is an equation described if the number of atoms of each element in the products equals the number of atoms of each element in the reactants? a.not spontaneous b.balanced c.an acid-base reaction d.spontaneous​

Answers

Answer: balanced

Explanation: i just took the test! :) hope this helps

In an equation, the number of atoms in products is equal to the number of atoms in reactant represents a balanced equation. Hence, option B is correct.

What are chemical reactions?

It is a process in which one or more substance is converted into the other substances, is called chemical reactions. The chemical equation is given as A + B = C + D. A, B are reactants and C, D are products.

There are several types of chemical reactions like balanced reactions, spontaneous reactions, combination reactions and decomposition reactions.

Spontaneous reaction is a chemical reaction, in which the reactant is converted into product without the supply of external energy. The spontaneous reaction exothermic. The example for spontaneous reaction is combustion reaction.

Non-spontaneous reactions is a type of chemical reaction, in which the reactants can not be converted into product by its own. This reaction requires a external energy to undergo the chemical reaction. Electrolysis of water is an example of non-spontaneous reactions.

When there is exchange of one or more hydrogen ions (H⁺) between the reactant and product molecules is called acid-base reactions. This thpe of reaction is called as neutralisation reactions.

Balanced reactions is defined as the number of atoms in reactant is equal to the number of atoms in products. It is also said to be that when there is no inequalities between reactant and product.

Hence, if number of atoms in both reactant and product is equal, then it is called Balanced reactions. Thus, the correct option is B.

Learn more about Balanced reaction:

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Which statements about the geocentric model are false? Select the two correct answers.
A. It explains why Mars appears to move backward for a few months approximately every two years.
B. It shows the Sun at the center of the solar system.
C. It shows Earth at the center of the solar system.
D. It shows the orbits of the planets as circular.

Answers

Answer:

pretty sure its C

Explanation:

maybe C thats my opinion

Una carga de 4 nC es transportada desde el suelo hasta la superficie de una esfera cargada con un trabajo de 7 X 10-5 j. Determinar el potencial eléctrico de la esfera

Answers

Respuesta:

2 × 10⁴ V

Explicación:

Paso 1: Información provista

Carga transportada (q): 4 nCTrabajo realizado (W): 7 × 10⁻⁵ J

Paso 2: Convertir q a Coulomb

Usaremos el factor de conversión 1 C = 10⁹ nC.

4 nC × 1 C/10⁹ nC = 4 × 10⁻⁹ C

Paso 3: Calcular el potencial eléctrico (V) de la esfera

Usaremos la siguiente fórmula.

V = W/q

V = 7 × 10⁻⁵ J/4 × 10⁻⁹ C = 2 × 10⁴ V

a sample of alien goo has a density of 45g/cm^3 and a volume of 10cm^3. What is its mass?

Answers

Answer:

mass= 4.5 g

Explanation:

density = mass/ volume

given :

density = 45 gm/cm^3

volume = 10cm^3

now

45 = mass / 10

45/10 = mass

mass = 4.5 g

can someone please solve this

Answers

Answer:

The gravity is pulling the diver downwards but the rotation of the body means gravity cant pull him down as quickly

Explanation:

!!pls help!! Where does the electricity in your home come from? What types of fuels are used to generate this electricity

Answers

Answer:

Electricity comes from power generation plants (some homes have solar cells which produce most of the electricity

Older plants use coal and gas as fuels for power generation (if you see a train go thru with 100 or so cars loaded with coal, that may be from Wyoming and going to a coal fired plant)

Wind farms are becoming more plentiful and produce some portion of the electricity generated

Solar cell farms are also used to produce a small portion of electricity

Heat pumps can use geothermal sources (heat from the ground)

Wave motion of water can also be used to produce electricity

What is the net force acting upon this object? *

3N : to the left
5 N : to the right
Answers to choose from:
2 N Right
BN
2 N Left
5 N Right

Answers

2 N Right

.. .. .. .. .. .. .. ..

Answer:

2 N Right

Explanation:

Net force = 5 - 3

= 2 N to the Right

Explain the effects of expansion of water on aquatic life​

Answers

Answer:

The anomalous expansion of water helps preserve aquatic life during very cold weather. When temperature falls, the top layer of water in a pond contracts, becomes denser and sinks to the bottom. If the temperature falls further, the top layer expands and remains on the top till it freezes.

A 1220-w hair dryer is used by several members of the family for a total of 30 min per day during a 30 day month. How much elecrical energy is consumed by the hair dryer during the month give your answer in kilowatt hours

Answers

Answer:

Energy = 18.3 Kilowatt-hour

Explanation:

Given the following data;

Power = 1220 Watts

Time = 30 * 30 = 900 minutes to hours = 900/60 = 15 hours

To find the energy consumption;

Power can be defined as the energy required to do work per unit time.

Mathematically, it is given by the formula;

[tex] Power = \frac {Energy}{time} [/tex]

Making energy the subject of formula, we have;

Energy = power * time

Energy = 1220 * 15

Energy = 18300 Joules

To convert energy to Kilowatt-hour;

Energy = 18300/1000

Energy = 18.3 Kilowatt-hour

My next photo
How's it​

Answers

Answer:

Good............................

how does increasing and decreasing the temperature affect the kinetic energy of molecules?​

Answers

Answer:

Amontons's law. If the temperature is increased, the average speed and kinetic energy of the gas molecules increase. ... If the gas volume is decreased, the container wall area decreases and the molecule-wall collision frequency increases, both of which increase the pressure exerted by the gas

what is the another name ffo

Answers

Answer:

sorry buh I don't get the question

A van accelerates from 4m/s to 20m/s in 8s. How far does it travel in this time?​

Answers

Answer:

96 m

Explanation:

Given,

Initial velocity ( u ) = 4 m/s

Final velocity ( v ) = 20 m/s

Time ( t ) = 8 s

Let Acceleration be " a ".

Formula : -

a = ( v - u ) / t

a = ( 20 - 4 ) / 8

= 16 / 8

a = 2 m/s²

Let displacement be " s ".

Formula : -

s = ut + at² / 2

s = ( 4 ) ( 8 ) + ( 2 ) ( 8² ) / 2

= 32 + ( 2 ) ( 64 ) / 2

= 32 + ( 2 ) ( 32 )

= 32 + 64

s = 96 m

Therefore, it travels 96 m in time 8 s.

A solenoid coil 10cm long has 40 turns cm-1. The current rises from zero to its maximum value of 5.0000 A and 0000.01s when the switch is closed. Find the energy stored in magnetic field if the area of cross section of solenoid be 28 centimeter square.

Answers

Answer:

Explanation:

Energy stored in a solenoid per unit volume = B₀² / (2μ₀)

B₀= μ₀ n I₀

n is no of turns per unit length .

Energy stored in a solenoid per unit volume = ( μ₀ n I₀)² / (2μ₀)

=μ₀n²I₀²/2

n = 40 turns / cm = 40 x 100 turns per meter.

I₀ = 5000A .

Putting the values

Energy stored in a solenoid per unit volume

= 4π x 10⁻⁷ x 40 x 10² x 5000² /2

= 1256 J/ m³

Volume of solenoid = cross sectional area  x length

= 28 x 10⁻⁴ x .10 = 2.8 x 10⁻⁴ m³

Total energy stored = 1256  J / m³ x 2.8 x 10⁻⁴ m³

= .35 J .

What 3 things do you need to make an electromagnet ?

Answers

Answer:

1. Battery

2. Copper wire

3. Nail or piece of metal (zinc, iron, or steel).

Answer:

magnet coppers wire and piece of metals

Which energy transformation occurs in plants, allowing them to make food?

Answers

Photosynthesis is the one
Other Questions
Last year (2016), Sarasota Condos installed a mechanized elevator for its tenants. The owner of the company, Ron Richter, recently returned from an industry equipment exhibition where he watched a computerized elevator demonstrated. He was impressed with the elevator's speed, comfort of ride, and cost efficiency. Upon returning from the exhibition, he asked his purchasing agent to collect price and operating cost data on the new elevator. In addition, he asked the companys accountant to provide him with cost data on the companys elevator. This information is presented below.: Old Elevator New Elevator Purchase price $103,500 $159,000 Estimated salvage value 0 0 Estimated useful life 5 years 4 years Depreciation method Straight-line Straight-line Annual operating costs other than depreciation: Variable $34,000 $11,000 Fixed 23,900 8,200Annual revenues are $241,000, and selling and administrative expenses are $30,000, regardless of which elevator is used. If the old elevator is replaced now, at the beginning of 2017, Bramble Condos will be able to sell it for $25,900.Required:Determine any gain or loss if the old elevator is replaced. A different random sample of 1,000 people yielded the results recorded in table 2. Use this data to answer the questions that follow.Part AWhat percentage of Americans would you predict wear corrective lenses?NOTE: this is table 2 just in case you wanted to know or if u got confused/just a double check :) Select which word or pair of words correctly completes the following sentence regarding The Bully. Based on the events of the story, the reader can assume that Ramon acts than J.T. Hey, can you describe 5 minutes the picture and say what it symbolizes please? what is jute sacks ? Mrs. Reids storage bin is 3 feet long, 2 feet wide, and 5 feet tall. Can she fit 34 boxes that each has a volume of 1 cubic foot in her bin? What can the reader conclude about ecosystems based on the information in this passage?Ecosystems Ecosystems are are always always distinctly distinctly different different and and unique.unique.Ecosystems Ecosystems are are interrelated interrelated with with other other ecosystems ecosystems surrounding surrounding or or including including them.them.Ecosystems Ecosystems are are slow-slow-developing developing entities entities of of biological biological communitiesmunities.Ecosystems Ecosystems are are clusters clusters of of communal communal habitats habitats in in an an area.area. Need help asappppp please find the solution of given expression,[tex] \sqrt{216 \times 6} [/tex] Why is building a government after being freed a major problem for many of these countries? What was the factory percentage of the Union? 65 76 85 55 Help pls please solve thisssssszzzszzsszzssss No links Choose the correct affirmative t command.Write in your notebook!A. Escribiendo en tu cuaderno!B. 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