Which statement about the photoelectric effect is true?

A When light acts as a wave, electrons are removed from a metal,

B. It occurs when an electric current causes light to be produced,

C. An electric current is produced when light shines on a surface,

D. It occurs any time an electric current is produced.

Answers

Answer 1

Answer: A

Explanation:

The photoelectric effect was first proposed by Einstein. He claimed that when a light wave comes in contact with an electron, it has the ability to strip that electron from its atom. It depends on how much energy the light wave is carrying, and what type of atom the light is hitting. We use the photoelectric effect in garage motion sensors.


Related Questions

An object is in simple harmonic motion. of the following quantities related to the object, which set of three can have maximum magnitudes at the same instant of time?.

Answers

The amplitude, restoring force and speed of an object undergoing simple harmonic  motion may have maximum magnitudes at the same instant of time.

What is simple harmonic motion?

Simple harmonic motion is a regular repeating motion. The acceleration of a simple harmonic motion is always directed towards the center of the motion.

There are three  quantities related to the object that can have maximum values at the same time and these are;

AmplitudeRestoring forceSpeed

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Which of the following determine the chemical properties of an element?

A)​​​​​​Its protons

B)Its inner shell electrons

C)The size of its nucleus

D)Its valence electrons

Answers

Answer:

D, valence electrons.

Explanation:

Since the number of shells are dependent on the number of valence electrons, which determines the period of the element. Because each shell of an element holds a total of 8 valence electrons, there is a chemical association that is being made between the outer electrons and the atom.

Answer:

The correct answer is D. Its valence electrons.

Explanation:

The valence electrons are those that participate in reactions with other elements.  The fewer valence electrons that an element has, the less stable it becomes; an element with a full valence electron shell does not frequently interact with other elements.  In this way, the valence electrons determine the chemical properties of an element.

Hope this helps!

how much time does it required for an airplane to reach its take off speed of 77 m/s if it starts from rest and its average acceleration is 8.2 m/s^2

Answers

Answer:

t = 9.38 seconds

Explanation:

Given that,

Initial speed of the airplane, u = 0 (at rest)

Final speed of the airplane, v = 77 m/s

Acceleration of the airplane, a = 8.2 m/s²

We need to find the time required for the airplane to accelerate. The formula of acceleration is given by :

[tex]a=\dfrac{v-u}{t}\\\\t=\dfrac{v-u}{a}\\\\t=\dfrac{77-0}{8.2}\\\\t=9.38\ s[/tex]

So, the time taken by the airplane is 9.38 seconds.

Imagine that you are in a space station in the vacuum of outer space, far from any planet. There is no air in space, so there is no friction. There is also very little gravity. You throw a ball out the door of the space station. Use Newton's first law of motion to predict what will happen to the motion of the ball.

Answers

Answer:

The ball will continue to move at a constant speed forever until another force stops it.

Explanation:

Newton's first law of motion can be seen as a law of inertia. It explains that an object at rest or in a state of uniform motion will remain in that state unless it is acted upon by an external force.

Following the above, when the ball is thrown into space, the ball will continue to move with the velocity with which it was thrown until it comes in contact with another object that stops it. If this does not happen, it will continue to drift forever at that velocity.

A 30.6 kilogram object is pulled by a horizontal force of 243 newtons causing it to accelerate at 5 meters per second squared. What is the force of friction acting on the
object? Calculate the coefficient of friction of the two surfaces.

Answers

Answer:

Ffriction = 90 N

coefficient = 0.3

Explanation:

First, note that the sum of all the forces in the x directions equals the mass multiplied by the acceleration in the x direction.

assuming the direction of the pulling force is positive,

243 N - Ffriction = m * a

m= 30.6 kg

a= 5 m/s/s

Ffriction= 243 - m*a

Ffriction= 243 - (30.6)(5)

Ffriction=90 N

The force of friction is equal to the coefficient of friction multiplied by the normal force on the object. Because the pulling force is completely horizontal, the normal force of the object is equal to its weight, which is m * g, or (30.6 kg)(9.8 m/s/s) = 299.88 N

Ffriction = coefficient * Fnormal

90 = coefficient * 299.88

coefficient = 0.3

A projectile is launched straight up. From launch to landing back down takes 8s.
What is its launch velocity?

Answers

39.2 m/s is the launch velocity.
This will make the velocity zero after 4 seconds, and then 32.9m/s after 8 seconds as it lands back down.

If the Voltage is increased Current decrease what happens to the resistance​

Answers

Sorry im need the points

Please help me answer this science question.
A.) 1
B.) 2
C.) 3
D.) 4
Thank you!
Grade: 6/middle school
Subject: Science

Answers

the answer is number 4 as the iron filings are strongest at the poles

In a model AC generator, a 502 turn rectangular coil 8.0 cm by 23 cm rotates at 120 rev/min in a uniform magnetic field of 0.61 T. (a) What is the maximum emf induced in the coil

Answers

Answer:

9896

Explanation:

multiply them all together

The figure shows an overhead view of a 2.10 kg plastic rod of length 1.20 m on a table. One end of the rod is attached to the table, and the rod is free to pivot about this point without friction. A disk of mass 55.0 g slides toward the opposite end of the rod with an initial velocity of 26.5 m/s. The disk strikes the rod and sticks to it. After the collision, the rod rotates about the pivot point.
(a)What is the angular velocity, in rad/s, of the two after the collision?
(b)What is the kinetic energy, in joules, before and after the collision?
KEi
=
J
KEf
=
J

Answers

(a) The angular velocity of the system after the collision is 1.61 rad/s.

(b) The kinetic energy before collision is 19.31 J and the kinetic energy after collision is 1.45 J.

Conservation of angular momentum

The angular velocity of the system is determined by applying the principle of conservation of angular momentum.

Li = Lf

P x r = Ifωf

mv x r = Ifωf

[tex]\omega _f = \frac{mvr}{I_f} \\\\\omega _f = \frac{mvr}{\frac{1}{3}Mr^2 + mr^2 } \\\\\omega _f = \frac{mvr}{r^2(\frac{1}{3}M + m )}\\\\\omega _f = \frac{mv}{r(\frac{1}{3}M + m )}\\\\\omega _f = \frac{0.055 \times 26.5}{1.2(\frac{2.1}{3} \+ \ 0.055)} \\\\\omega_f = 1.61 \ rad/s[/tex]

Kinetic energy before the collision

Kinetic energy before the collision is calculated as follows;

[tex]K.E_i = K.E_{ball} + K.E _{rod}\\\\K.E_i = K.E_{ball} + 0\\\\K.E_i = \frac{1}{2} \times m \times v^2\\\\K.E_i = \frac{1}{2} \times 0.055 \times 26.5^2\\\\K.E_i = 19.31 \ J[/tex]

Kinetic energy after the collision

The kinetic energy after the collision is calculated as follows;

[tex]K.E_f =\frac{1}{2} I_f \omega_ f^2\\\\K.E_f = \frac{1}{2} (\frac{1}{3}Mr^2 + mr^2)\omega _f^2\\\\K.E_f =\frac{1}{2} [\frac{1}{3}(2.1)(1.2)^2 + (0.055)(1.2)^2]\times (1.61)^2\\\\K.E_f = \frac{1}{2} (1.008 + 0.114) \times (1.61)^2\\\\K.E_f = 1.45 \ J[/tex]

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Analyze Ultrasound uses high-frequency
sound waves to get images of the insides of
our bodies. Sound waves would travel the
fastest through which of the materials listed
in the chart?

Answers

Answer:

we have sung a song .change into simple present tense

What does high resistance mean?
A. Electrons are squeezed together, creating friction as
they flow.
B. Electrons flow through a wire without touching each
other.
C. Electrons have an easy time completing the circuit.
D. Electrons flow backwards through the circuit.

Answers

Answer:

i think it's A

because if there is more friction then it will create more hindrance for the current to flow which is ultimately called resistance .

PLEASE HELP, IS URGENT ​

Answers

Answer: around 65.

Explanation:

You are given a diameter of 10 cm (this is x value). find what y value is equal to at those 10 cm. You’ll see that it’s aroun 65

How long does it take for uranus to rotate on its axis.

Answers

Answer: 17 hours

Explanation:

A quarter rolls off a table with an initial horizontal velocity of 0.24 m/s. If the quarter lands 0.42 seconds later on the ground. How far from the table did it land?

Answers

Answer:

0.10 m

Explanation:

Given in the x direction:

v₀ = 0.24 m/s

a = 0 m/s²

t = 0.42 s

Find: Δx

Δx = v₀ t + ½ at²

Δx = (0.24 m/s) (0.42 s) + ½ (0 m/s²) (0.42 s)²

Δx ≈ 0.10 m

The distance from the table with the horizontal velocity of 0.24 m/s and time t is 0.42 s is 0.10m.

What is velocity?

Velocity is defined as the rate of displacement per unit time. It equals the speed along with the direction. Velocity is the vector quantity as it has both magnitude and direction.

The velocity can be classified as instantaneous velocity and average velocity. Average velocity is obtained by the ratio of total displacement to total time. The unit of velocity is m/s.

From the given,

Initial velocity (u) = 0.24 m/s

time = 0.43 s

acc (a) = 0

distance (s) =?

By using the equation of motion:

s = ut + 1/2 (at²)

 = 0.24×0.42 + (0×0.42×0.42)/2

 = 0.10 + 0

s = 0.10 m

Thus, the distance traveled from the table is 0.10 m.

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A microwave oven has a power of 1800 W and the potential difference applied from the mains is 230 V. What are its current and resistance?

Answers

Answer:

I = 7.826A

R = 29.38 Ω

Explanation:

First, let us find the current of the microwave.

Let us use the below formula for that.

Power = Voltage × Current

Current = Power ÷ Voltage

             = 1800w ÷ 230v

             = 7.826 A

And now let us find the resistance using the below formula.

Voltage = Current × Resistance

Resistance = Voltage ÷ Current

                   = 230V  ÷ 7.826A

                    = 29.38 Ω

Nima explains that visible light occupies the range of the electromagnetic spectrum that humans can see. What other characteristics of visible light can Nima share with her students

Answers

Other characteristics that Nima can share with her students are as follows:

Visible light ranges in wavelength of 400 - 700nmVisible light is between the ultraviolet and infrared rays of the EM spectrum.

What is visible light?

Visible light is one of the components of the electromagnetic spectrum (EM). It is the only part of the EM spectrum that is visible to human eyes.

According to this question, Nima has already shared this characteristics of visible light with her student.

Other characteristics that Nima can share with her students are as follows:

Visible light ranges in wavelength of 400 - 700nmVisible light is between the ultraviolet and infrared rays of the EM spectrum.

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Cellular respiration transforms oxygen and sugars into carbon dioxide and water. Which of the following best explains this reaction?

A Physical change, only phases of matter changed
B Chemical change, new substances were formed
C Physical change, solids were changed into gases
D Mixtures and solutions were formed from the materials

Answers

B. Chemical change,new substances were formed

Identify the functions of Respiratory and Circulatory Systems page 134

Answers

An organism's circulatory system pumps blood, while its respiratory system regulates its gas exchange ( carbon dioxide and oxygen). The circulatory system consists of the blood, heart, blood arteries, and lymph nodes, while the nervous system consists of the brain, spinal cord, and nerves. Like the respiratory system, the circulatory system is made up of a network of blood vessels that transport oxygen and carbon dioxide throughout the body. Taking in oxygen and exhaling carbon dioxide are the primary functions of the circulatory system and the respiratory system, respectively. After entering the heart, deoxygenated blood travels to the lungs, where it is re-oxygenated. Oxygen is necessary for both systems to function.


What is the best inference for the height of the plant after 35 hours?

Answers

Option D, 1.95 cm

1.8+2.1=3.9/2 = 1.95

What element is a Transition Metal similar to Silver but has less protons?

Answers

Zinc is the first element of the twelfth column of the periodic table. It is classified as a transition metal. Zinc atoms have 30 electrons and 30 protons with 34 neutrons in the most abundant isotope.

Which planet moves the fastest and which planet moves slowest?

Answers

Answer:

d is the fastest and c is the slowest

Explanation:

physics

Answer:

Neptune will move the fastest

Mercury will move the slowest

Explanation: Because what ever is closer to a object will move the slowest and something further away will have to go faster to keep up with the object that is closer.

applied a force of 55 N to accelerate a 10 kg box at 3 m/s2 along a horizontal surface. What is the magnitude of the frictional force?

Answers

Answer:

25N

Explanation:

if you calculate it right the answer will be 25

A boy weighing 50 kg is running at 2m/s. What is its kinetic energy? *
10 points

Answers

The answer is 100.
The formula is KE = 1/2mv^2
Then you plug in 50 to the m
And 2 to the v . That’s how I got 100 .
Hope this helps

The weather in Detroit will likely be rainy because Mike noticed a(n) _________ near Detroit.
Question options:


occluded front


stationary front


cold front


warm front

Answers

Answer: stationary front

Explanation:

HELPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!






















































How old is the sun?

Answers

Answer:

4.6 billion years

Explanation:

The right-hand rule applies to what kind of charge?.

Answers

The right hand rule applies to a positive charge

What letter would be a likely place
for Mystery Element #2 to be located
on the Periodic Table?
Mystery Element #2
•Silver
•Solid
В с
Melting Point 725.05C
Good conductor of heat
and electricity
•Malleable
A
D

Answers

A is the answer sorry if Im wrong tho

The mystery element on the periodic table that have melting point of 725.05c , that is malleable, good conductor of heat is Barium.

What is periodic table?.

Periodic table is the table that shows the classification of elements into groups and periods which classify them base on their unique and comon characteristics within each group.

Therefore, The mystery element on the periodic table that have melting point of 725.05c , that is malleable, good conductor of heat is Barium.

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Which of the following people came up with the term “hypnosis”?

Answers

james braid came up with the term hypnosis

Answer:

A- James Braid

Explanation:

e2020

Which property describes the temperature at which a liquid changes to a gas?

Group of answer choices

freezing point

boiling point

melting point

condensation point

Answers

Answer:

Boiling Point

Explanation:

When a liquid changes to a gas is called the boiling point.

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