Please solve it as soon as possible with steps

So, we know that this question is about photoelectric effect.

What is photoelectric effect?

-Photoelectric effect is a phenomenon where electrons are released from a material whenever an electromagnetic radiation such as light, hits it.

-This phenomenon is first discovered by Heinrich Rudolf Hertz in 1887 whereas Albert Einstein, in 1905, resolved the conflict between the photoelectric effect and Maxwell's electromagnetic wave theory of light.

Now to your question, the intensity of light only determines the number of the electrons released, not their maximum kinetic energy because this are proportional to the light's frequency.

Also, there is no time lag detected between the entry of radiation and the emission of electrons in experiments held.

So, with letter A and C out, we can therefore conclude that the answer for this is Letter B

The correct answer is B: the number of electrons ejected per second

The Einstein photoelectric equation states that;

[tex]KE = hf - hfo[/tex]

Where

KE = kinetic energy of the ejected photo electrons

h = Plank's constant

f = frequency of incident light

fo = threshold frequency.

The kinetic energy of ejected photoelectrons depends on frequency of incident photon and not on the intensity of the incident photon.

However, the number of photoelectrons ejected per second depends on the intensity of the incident blue light.

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Answer:

Light consists of photons, which are produced when an object's atoms heat up. Light travels in waves and is the only form of energy visible to the human eye.

Explanation:

Now What is light?

-Light ( or light energy ) is defined as a form of electromagnetic radiation and a type of kinetic energy.

-Light is made up of photons. Photons is the basic unit of light. They are produced when an object's atom is subjected to heat. The more the atoms are heated, the more photons are created.

-Light travels in the form of a wave but it does not require any medium for transmission.

-Light travels so fast, nothing is faster than it. It travels at a constant speed of 186,282 miles/sec ( 300,000 km/sec ) in vacuum and whether the source is moving or stationary.

-Light can be measured in either joules, calories ( energy units ), quanta and einsteins ( quantum units ). Conversion from one unit to another heavily depends on wavelength.

Now an unaided human eye can only see the visible light, namely red, orange, yellow green, blue, indigo and violet (Roy G Biv) but light also comes in other forms that we cannot see, they are named, radio wave, microwave, infrared, ultraviolet, x-ray and gamma ray.

Complete Question

A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutions. At what rate is the flywheel spinning when the power comes back on(in rpm)? How long after the beginning of the power failure would it have taken the flywheel to stop if the power had not come back on, and how many revolutions would the wheel have made during this time?

Answer:

[tex]\theta=274rev[/tex]

Explanation:

From the question we are told that:

Angular velocity [tex]\omega=510rpm[/tex]

Mass [tex]m=40.kg[/tex]

Diameter d [tex]75=>0.75m[/tex]

Off Time [tex]t=40.0s[/tex]

Oscillation at Power off [tex]N=210[/tex]

Generally the equation for Angular displacement is mathematically given by

 [tex]\theta_{\infty}=\frac{w+w_0}{t}t[/tex]

 [tex]w=\frac{2*\theta_{\infty}}{t}-w_0[/tex]

 [tex]w=\frac{28210}{40*(\frac{1}{60})}-510[/tex]

 [tex]w=120rpm[/tex]

Generally the equation for Time to come to rest is mathematically given by

 [tex]t=(\frac{\omega_0}{\omega_0-\omega})t[/tex]

 [tex]t=(\frac{510}{510-120rpm})(40.0)(\frac{1}{60})[/tex]

 [tex]t=0.87min[/tex]

Therefore Angular displacement is

 [tex]\theta =(\frac{120+510}{2})0.87[/tex]

 [tex]\theta=274rev[/tex]

Answer: E- An opera singer breaks a thin glass with only the use of her high frequency voice

Explanation:

Resonance is when a person is able to evoke emotions or when a person is deep in character. It is the ability to evoke memories, images and emotions.

Examples of resonance include old pictures which has emotional attachments, feel voice of a singer etc.

Therefore, the event that is an example of resonance is an opera singer breaks a thin glass with only the use of her high frequency voice.

Answer:

36000

Explanation:

1/2mv²=0.5×500×12²=36000j

Answer:

B

Explanation:

galvanometer has a small resistance ....

I dont know whether the answer is right...

Answer:

it's D

Explanation:

Answer:

v = 3.53x10⁻³ m/s.

Explanation:

We can find the velocity of the rock by energy conservation:

[tex] \Sigma E_{i} = \Sigma E_{f} [/tex]        

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

Where:

i is for initial and f is for final

k: is the stiffness of the rubber = 20 N/m

x: is the distance of the rubber compression = 5 mm = 0.005 m

m: is the mass of the stone = 40 kg

v: is the velocity =?

Hence, the velocity is:

[tex]v = \sqrt{\frac{kx^{2}}{m}} = \sqrt{\frac{20 N/m(0.005 m)^{2}}{40 kg}} = 3.53 \cdot 10^{-3} m/s[/tex]

Therefore, the velocity with which the stone leaves the catapult is 3.53x10⁻³ m/s.

I hope it helps you!  

Answer:

B) - 5.0 m

Explanation:

B is located on a positive location, 15m from the starting point A. Hence, since E is located a positive distance 10m from A, the difference becomes 10 - 15 = - 5.0 m

Answer:

The solution is neither acidic or basic,

PH < 7    acidic

PH = 7    neutral

PH > 7 basic

It is a measure of the (H+) hydronium concentration.

Answer: D

Explanation:

An elastic collision is a collision in which there is no net loss in kinetic energy in the system as a result of the collision. Both momentum and kinetic energy are conserved quantities in elastic collisions. Suppose two similar trolleys are traveling toward each other with equal speed.

Answer:

elastic collision

Explanation:

Answer: hey, i hope this hlps!~~~ Part of mental health is how well your mind processes and understands information and experiences. In contrast, emotional health involves your ability to manage and express the emotions that arise from what you have learned and experienced.

Explanation:

Answer:

Explanation:

T = 2π √ (m/k)

T / 2π = √ (m/k)

T√k = 2π √m

(T√k) / 2π = √m

( (T√k) / 2π)^2 = m

m = ( (7.5√82.5) / 2π)^2

m = 117.66 Kg

Answer:

1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;

i) The cost of manufacture of nichrome is low

ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting

iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element

iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater

v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied

2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level

Explanation:

Answer:

They break off large ice sheets found at the North and South poles.

Answer:

The answer is D

Explanation:

They break off large ice sheets found at the poles.

Answer:

Cost of energy = N230.4

Explanation:

Given the following data;

Time = 8 hours

Power = 1200 W

Voltage = 240 V

Cost of energy = N24

To find the cost of running an electric laundry iron;

First of all, we would determine the energy consumption of the iron.

Energy = power * time

Energy = 1200 * 8

Energy = 9600 Watt-hour = 9.6 Kwh (1 Kilowatts is equal to 1000 watts).

Next, we find the cost of energy;

Cost of energy = 9.6 * 24

Cost of energy = N230.4

Answer:

According to the law of conservation of energy, energy is neither created nor destroyed but changes from one form to another

The energy in the light bulb comes from the movement of electrons through the resistance of the coil of the bulb, therefore, the energy in the bulb is changed from electric energy to heat and light energy as follows;

The friction between the moving electrons and the resistive filament of the light bulb results in the slowing down of the rapidly moving electrons

The part change in the (kinetic) energy of the electrons moving through the filament of the bulb as they slow down is observed as sensible heat which causes the bulb to be hot

Another part of the change in energy is given seen as the light given off by the bulb filament in an incandescent bulb as the filament becomes very hot from the movement of the electrons which causes the bulb to glow (produce light), due to the incandescent characteristics of the filament

Explanation:

Answer:

it is difficult

my best answer would be a. 6

hope its right!!

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Explanation:

The half-life formula is

y = A*(1/2)^(x/H)

where A is the starting amount, H is the half-life, x is the time value and y is the amount after x units of time have passed.

I'll express the x and H values in terms of millions of years. So for example, when we say H = 500, then that really refers to 500 million years.

----------

In this case, we know that,

Let's use those values to solve for x. We'll need logs to cut the exponents down from the trees.

y = A*(1/2)^(x/H)

3 = 192*(1/2)^(x/500)

3/192 = (0.5)^(x/500)

0.015625 = (0.5)^(x/500)

log(0.015625) = log( (0.5)^(x/500) )

log(0.015625) = (x/500)*log(0.5)

(x/500)*log(0.5) = log(0.015625)

x = 500*log(0.015625)/log(0.5)

x = 3,000

Keep in mind that x is in millions of years. So saying x = 3,000 means 3,000 million years. This translates to 3,000*10^6 = 3,000,000,000 = 3 billion years.

It will take about 3 billion years for the 192 atoms to decay to only 3 atoms.

The amount of half-lives this occurs is x/H = (3,000)/500 = 6

So the time span of 3 billion years is the same as 6 half-lives when each half-life is 500 million years long.

Answer:

A

Explanation:

because she wants to practice science and A is the practical option.

Answer:

Uranium

Explanation:

The most important in atomic research is Uranium, Uranium Can be used as fuel for nuclear power plants and the nuclear reactors that run naval ships and submarines, so option A is correct.

The atom is the smallest unit of matter that may be divided without generating particles with an electrical charge. Additionally, it is the tiniest material with characteristics similar to chemical elements. As a result, the atom acts as the basic building block of chemistry.

Space makes up the majority of an atom. The rest is made up of a positively charged nucleus made up of protons and neutrons that are surrounded by a cloud of negatively charged electrons. The nucleus is small and dense when compared to electrons, which are the lightest charged particles in nature. Electric forces, link electrons to the nucleus of atoms, causing them to be drawn to any positive charge.

Uranium that has been "enriched" to have a higher concentration of U-235 can power nuclear power plants, and It can also be applied to nuclear weapons.

Therefore, uranium is the most important in atomic research.

To know more about atoms:

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Answer:

C. Alleles

Explanation:

Our genes are responsible for our phenotype (physical traits). Alleles is the only genetic term in there.

Answer:

electrons i think

Explanation:

Answer:

its not B1 or A1. must be A2 or C2

Explanation:

Answer:

(a) 0.71 mm

(b) 0.158 cubic cm

Explanation:

The width of one wire is the diameter of the wire.

(a) Let the diameter of each wire is d.

So, 10 d = 14.2 mm

d = 1.42 mm

radius of each wire, r = d/2 = 1.42/2 = 0.71 mm

(b) Length, L = 10 cm

The volume of the single wire is given by

[tex]V =\pi\times r^2\times h \\\\V =3.14\times 0.071^2\times 10\\\\V =0.158 cm^3[/tex]

Answer:

They are temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness. Together, these components describe the weather at any given time.

Answer:

the front of the human head from the forehead to the chin and ear to ear

Explanation:

Hope this helps