PLLLLLLEEEEESSEEEEE HELP!!!!!!!

In conclusion, to determine the threshold frequency, we compared the energy of the incident photons to the work function of the metal. By calculating the energy of the incident photons and the stopping potential, we found the work function and converted it back to frequency to obtain the threshold frequency of approximately 1.28 x 10^15 Hz.

The threshold frequency of a metal is the minimum frequency of light required to free electrons from the metal's surface. In this case, the incident light has a frequency of 2 x 10^15 Hz and a stopping potential of 3.0 V is observed.
To find the threshold frequency, we need to compare the energy of the incident photons with the work function of the metal. The work function is the minimum energy required to free an electron from the metal's surface.
The energy of a photon can be calculated using the equation

E = hf,

where E is the energy, h is Planck's constant (6.63 x 10^-34 J s), and f is the frequency of the light.
First, let's calculate the energy of the incident photons:
E = (6.63 x 10^-34 J s) x (2 x 10^15 Hz)
E ≈ 1.326 x 10^-18 J
Since the stopping potential is 3.0 V, this means the maximum kinetic energy of the emitted electrons is

3.0 eV (1 eV = 1.6 x 10^-19 J).

The maximum kinetic energy of the emitted electrons is equal to the energy of the incident photons minus the work function.
Let's set up an equation:
3.0 eV = 1.326 x 10^-18 J - work function
To find the work function, we convert the stopping potential from eV to joules:
3.0 eV x (1.6 x 10^-19 J/eV) = 4.8 x 10^-19 J
Now, we can solve for the work function:
4.8 x 10^-19 J = 1.326 x 10^-18 J - work function
Rearranging the equation:
work function = 1.326 x 10^-18 J - 4.8 x 10^-19 J
work function ≈ 8.46 x 10^-19 J
Finally, we can convert the work function back to frequency using the equation E = hf. Rearranging the equation to solve for the threshold frequency, we get:
threshold frequency = work function / h
Plugging in the values:
threshold frequency ≈ (8.46 x 10^-19 J) / (6.63 x 10^-34 J s)
threshold frequency ≈ 1.28 x 10^15 Hz
Therefore, the threshold frequency needed to free electrons from this metal is approximately 1.28 x 10^15 Hz.
In conclusion, to determine the threshold frequency, we compared the energy of the incident photons to the work function of the metal. By calculating the energy of the incident photons and the stopping potential, we found the work function and converted it back to frequency to obtain the threshold frequency of approximately 1.28 x 10^15 Hz.

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Answer:

As a pendulum moves toward the equilibrium position, velocity increases and acceleration decreases. As the pendulum moves away from the equilibrium position, velocity decreases and acceleration increases.

Explanation:

Using the law of conservation of energy, we know that Em1=Em2.

Em1 (at the highest point) = Eg + Ek, where Ek is 0

Em2 (at the equilibrium point) = Eg +Ek, where Eg is 0

This makes sense. At the highest point, the pendulum is at its maximum height. At this point, however, it stops moving, so its velocity is 0. At the equilibrium point, the pendulum is at its lowest height (i.e. h=0). At this point, however, its moving at its maximum velocity. This velocity is constant, which means that acceleration is 0.

Answer:

1) Increases

2) Decreases

3) Decreases

4) Increases

5) Maximum

Explanation:

As a pendulum moves toward the equilibrium position, velocity

✔ increases

and acceleration

✔ decreases

. As the pendulum moves away from the equilibrium position, velocity

✔ decreases

and acceleration

✔ increases

. Velocity is at a

✔ maximum

when acceleration is zero.

The force that acts on a jar of honey with a mass of 7.4 kg during its fall is gravitational force which is equivalent to 72.594 Newton.

The gravitational force acting on the jar during its fall can be calculated using the formula:

F = m × g

where m is the mass of the jar and g is the acceleration due to gravity (9.81 m/s²).

Thus, the force acting on the jar during its fall can be calculated as:

F = 7.4 kg × 9.81 m/s² = 72.594 Newton

Therefore, the jar experiences a force of approximately 72.594 Newton during its fall. It is important to note that this force is due to the acceleration due to gravity and is the same force that causes all objects to fall towards the earth at the same rate, regardless of their mass.

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Answer:

· Periodic table, in full periodic table of the elements, in chemistry, the organized array of all the chemical elements in order of increasing atomic number —i.e., the total number of protons in the atomic nucleus. When the chemical elements are thus arranged, there is a recurring pattern called the “periodic law” in their properties, in which elements in the same column (group) have similar properties.

its d btw

Explanation:

The angle made by the rope to the horizontal (x)

⇒ sin X = 25/95

X= sin^-1(25/95)

X = 15.25

The horizontal angle made by the made by the rope is 15.25°, when the child was pulling it with the force.

Force is defined as an outside force that has the power to alter the motion or rest of a body.

It can also be defined as a push or a pull that modifies or tends to modifies an object's uniform motion, state of rest, or modifies the object's direction or shape. It either accelerates items or increases their overall pressure.

It is a vector quantity.

There are basically seven types of force.

The rope's angle with respect to the horizontal (x)

sin X = 25/95

X= sin⁻¹(25/95)

X = 15.25°

Thus, the horizontal angle made by the made by the rope is 15.25°, when the child was pulling it with the force.

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The combined speed of the locomotive and railroad car after the collision is one-fifth of the initial speed of the locomotive.

The combined speed of the locomotive and railroad car after the collision can be determined using the law of conservation of momentum. According to this law, the total momentum of a system before a collision is equal to the total momentum of the system after the collision, provided that no external forces act on the system.

Assuming that the railroad car is initially at rest, the momentum of the locomotive before the collision is:

p1 = m1v1

where m1 is the mass of the locomotive and v1 is its velocity.

After the collision, the locomotive and railroad car are coupled together and move with a common velocity v2. The momentum of the combined system after the collision is:

p2 = (m1 + m2) v2

where m2 is the mass of the railroad car.

Since momentum is conserved, we can set p1 = p2 and solve for v2:

m1v1 = (m1 + m2) v

v2 = (m1v1) / (m1 + m2)

Given that the mass of the locomotive is four times that of the railroad car, we can write m1 = 4m2. Substituting this into the equation above, we get:

v2 = (4m2v1) / (4m2 + m2)

v2 = v1 / 5

Therefore, the combined speed of the locomotive and railroad car after the collision is one-fifth of the initial speed of the locomotive.

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Answer:

Resultant displacement is 29.2 km at north of west

Explanation:

To solve the problem, we have to use the rules of vector addition, resolving first each vector along the x- and y- direction.

Taking east as positive x direction and north as positive y- direction, we have:

- First displacement is 25.5 km east, therefore its components are

- Second displacement is 41.0 km northwest, so its components are

So, the components of the resultant displacement are

And so, the magnitude is calculated using Pythagorean's theorem:

And the direction is given by

Where the angle is measured from the west direction, since Rx is negative.

The photon energy of electromagnetic radiation with a wavelength of 465 nm is 4,2 x 10⁻¹⁹ J.

To determine the energy of the emitted light, we need a relationship to the wavelength of the light. In terms of the equation formula is

                                 E = hc/λ

Where h is Planck's constant and c is the speed of light and λ is the wavelength of light.

Planck's constant is 6.626 x10⁻³⁴ m² kg/s and the speed of light is 3x10⁸m/s. The wavelength is 465 nm = 465x10⁻⁹ m.

So,

E = hc/λ

E = (6.626 x10⁻³⁴)(3x10⁸)/465x10⁻⁹

E = 19.875 x 10⁻²⁶/465x10⁻⁹

E = 4,2 x 10⁻¹⁹ J

So, the energy of a photon is 4,2 x 10⁻¹⁹ J.

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Answer:

Energy

Explanation:

I am a scientist.

Answer:

12 years

Explanation:

12 years is correct because how long is Jupiter one year is 12 years

Answer:

False

Explanation:

As the mass of a neutron is slightly greater than the mass of a proton

The correct option is (c) Number of neutrons = number of protons

The right response is neutron. Neutron.

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Answer:

D. Newton's second law

Explanation:

Newton's second law of motion states that force of an object is a product of its mass and its acceleration.

Mathematically, F= ma where  m is mass and a is acceleration

So from the statement above : The acceleration of an object is proportional to the force applied to it and  inversely proportional to its mass , it can be seen from the formula variation as;

F= ma -----making a the subject of the formula

a= F/ m

a= 1/m * F --------- a  is inversely related to m  as you can see from 1/m but directly related to F  hence;

Increase in mass with the same force applied causes the body to accelerate slower where as when force increases, the body accelerates faster.

Answer:

In nuclear power plants, energetic neutrons are directed into a sample of the isotope uranium-235. ... A common fission reaction produces barium-141 and krypton-92. In this particular reaction, one uranium nucleus breaks into a barium nucleus, a krypton nucleus, and two neutrons

Answer:

The observer will say that galaxy 2 is moving away from galaxy 3 where he stands.

Explanation:

Since the galaxies are expanding, each one would move away from the others. Observers on all three galaxies have their frame of reference fixed on their own galaxies. Judging from their own galaxies, each observer will perceive the other galaxies moving away from his/or galaxy.

The observer at galaxy 3 will talk about galaxy 2 by doing is; he will say that galaxy 2 is moving far from him.

We are told that the universe is expanding and as such, the galaxies would be expanding and moving away from each other.

Since the galaxies are expanding, it means that they will be moving away from each other.

From time dilation principle, an observer at galaxy 3 will say that galaxy 2 is moving far from him.

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Answer:

a whole new glacier will start because the other one is melting

Answer:

a. 6 A

b. 3 V

Explanation:

a. By using Kirchoff's Junction Rule, which states that the current flowing into a junction must equal the current flowing out of it. As you can see in the first 3-way split, the current splits into 3A, 2A, and 1A. This means that when the 3 wires rejoin, the current must have a magnitude equal to the total of the current flowing in all 3 branches, which would equate to 3+2+1 = 6 A.

b. Voltage differences across branches of a parallel circuit are identical. This means that we can treat the 3 resistors as one, and say that the voltage drop across that whole area is 3 V. Since that is the only voltage drop in the circuit, the battery's voltage drop must also be 3 V to equate to it. This is explained by Kirchoff's Loop Rule.

a)

When a standing wave propagates through a string, the length of the string is a multiple of half the wavelength:

The factor n corresponds to the number of the harmonic. Then, the first harmonic is given by the condition n=1:

As we can see, the wavelength of the first harmonic is two times the length of the string.

Then, the wavelength of the first harmonic can be found by replacing the length L=63cm:

b)

The product of the wavelength and the frequency is the speed of the wave:

Replace λ=126cm=1.26m and f=330Hz to find the speed of the wave on the E-string:

c)

The frequency of the n-th harmonic is given by:

On the other hand:

Then:

Notice that v/2L is the frequency of the first harmonic (fundamental frequency). Then:

Replace the fundamental frequency of 330Hz and n=2,3,4 to find the second, third and fourth harmonic frequencies:

d)

Replace n=3 into the expression for the wavelength of the n-th harmonic to find the wavelength of the third harmonic:

Therefore, the answers are:

a) 126cm

b) 416m/s

c) 660Hz, 990Hz, 1320Hz

d) 42cm

Answer:

Consider a satellite with mass Msat orbiting a central body with a mass of mass MCentral. The central body could be a planet, the sun or some other large mass capable of causing sufficient acceleration on a less massive nearby object. If the satellite moves in circular motion, then the net centripetal force acting upon this orbiting satellite is given by the relationship

Fnet = ( Msat • v2 ) / R

Explanation:

The acceleration of the satellite released from a spacecraft orbiting a planet at an altitude of 120 km and the planet has a mass of 5.2 x 10^23 kg and a radius of 2800 km is 4.426 *  \(10^6\)  \(m/s^2\).

The term "acceleration" refers to the rate and direction at which velocity varies over time. Acceleration is the change in direction or speed of an object or points moving ahead. The frequent change in direction causes motion on a circle to rise even when the speed remains constant.

For all other motions, these effects increase the acceleration. A vector quantity, acceleration, is something that has both a magnitude and a direction. Velocity is a vector quantity as well.

Given:

The altitude of the spacecraft, h = 120 km,

The mass of the planet, m = \(5.2 * 10^{23}\) kg,

The radius of the planet, r = 2800 km.

Calculate the acceleration by the formula given below,

A = \(G* m /r^2\)

Here, A is the acceleration, G is the gravitational constant,

Substitute the values,

A = 6.674 * \(10^{-11}\) *5.2 * \(10^{23}\) / \(2800^2\)

A = 4.426 *  \(10^6\)  \(m/s^2\)

Therefore, the acceleration of the satellite is 4.426 *  \(10^6\)  \(m/s^2\)

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v(speed) = wavelenght x frequency

v = 0.579 m x 4 hz = 2.32 m/s

The reference equality is tested using the == operator. True. If obj1 and obj2 refer to same object, then obj1 == obj2 is true. True. A String object cannot be changed.

In programming, a string is a form of data that is used to data type rather than integers. Letters, numbers, symbols, and even spaces can all be found in a string, which is a collection of characters. In order for it to recognized as a string, it needs to be encapsulated in quotation marks.

A string is frequently implemented as just an array data structure of bits (or words) that records a sequence of elements, usually characters, using some text encoding. Typically, a string is considered to be a data type.

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Answer:

C

Explanation:

three bricks means 3 times the weight, so 6/3=2

ita called hematopoiesis

D. 1 N = 1 kg-m/s²

Explanation

Force can be defined as the push or pull on an object with mass that causes it to change its velocity, for example the force of gravity , this force pushes us to the cneter of the earth,

so

SI( international system of units) is the metric system that is used universally as a standard for measurements, the units for mass and acceleration are

therefore, the units of force would be

by definition

therefore, the answer is

D. 1 N = 1 kg-m/s²

I hope this helps you

Split F₁ into its horizontal and vertical components:

F₁ = F₁ cos(θ) i + F₁ sin(θ) j

(boldface = vector; regular font = magnitude)

By Newton's second law, if the object is in equilibrium, then

• the net horizontal force on the block is

∑ F = F₁ cos(θ) - F₃ = 0   →   F₁ cos(θ) = 70 N

• the net vertical force is

∑ F = F₁ sin(θ) + F₂ - W = 0   →   F₁ sin(θ) = 65 N

Recall that cos²(θ) + sin²(θ) = 1 for any θ, so we have

(F₁ cos(θ))² + (F₁ sin(θ))² = (70 N)² + (65 N)²

F₁² = 9125 N²

F₁ = √(9125 N²) ≈ 95.5 N