(please help me)

If a wave has a wavelength of 13 meters and a period of 0.005, what's the velocity of the wave?
A. 260 m/s
B. 1,300 m/s
C. 2,600 m/s
D. 1,560 m/s
(please dont type any wrong answer on porpuse)

Answer:

The protons will shift towards the negatively charged rod and the electrons will shift away

Explanation:

When negatively charged rod is brought near it , in sphere protons ( positively charge ) get attracted on the surface and electron get away (negatively charge) due to induction

Charging by induction is a process by which a neutral body can be charged electrostatically in the presence of a negatively or positively charged body.

Whenever a charged body is placed over a neutral conducting material that conducting material will induce an opposite charge to the charged body because of induction . Example : if charged body have positive charge than conducting material  will induce a negative charge on it

hence , when negatively charged rod is brought near it , in sphere protons ( positively charge ) get attracted on the surface and electron get away (negatively charge) due to induction

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The circular but relatively flat portion of the galaxy is the Disk

A galaxy that resembles a circle is known as a ring galaxy. Art Hoag's 1950 discovery of Hoag's Object is an illustration of a ring galaxy. Many big, relatively young blue stars that are quite brilliant can be found in the ring.

Galactic disks are thin, essentially circular collections of stars, gas, and dust; this matter revolves around a common core in almost circular orbits. As a result of this rotation, many disks have lovely spiral patterns, and some have distinct bars crossing their centres.

Nearly all of our galaxy's gas, dust, hot young stars, and star-forming regions are present there. When viewed from above, the disk reveals spiral arms that contain the majority of the ISM's cool, dense regions.

Therefore, Our galaxy's disk is incredibly narrow, only around 100 times wider than its own height.

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Answer:

d. Work is done on the gas

Explanation:

We are considering an isobaric compression, which means:

- Isobaric: the pressure of the gas is constant

- Compression: the volume of the gas is decreasing

For an isobaric compression, the volume done BY the gas is

[tex]W=p \Delta V= p (V_f -V_i)[/tex]

where

p is the gas pressure

[tex]V_f[/tex] is the final volume of the gas

[tex]V_i[/tex] is the initial volume of the gas

If the sign of W is positive, it means that the gas is doing work on the surrounding; if the sign of W is negative, it means that the surrounding is doing worn ON the gas.

In this case, since it is a compression, we have that the final volume is smaller than the initial volume:

[tex]V_f < V_i[/tex]

Therefore, the sign of W is negative, and therefore work is done ON the gas by the surroundings.

Final answer:

In an isobaric compression, work is done on the gas by the force exerted on the movable piston.

Explanation:

In an isobaric compression of an ideal gas,(option d) work is done on the gas. This means that energy is transferred to the gas through mechanical work. To understand this, let's consider a piston-cylinder system.

During an isobaric compression, the gas is compressed while the pressure remains constant. The gas particles push against the piston, causing it to move, and thus work is done on the gas.

This work is done by the force exerted on the movable piston, which causes a displacement. As a result, the volume and temperature of the gas decrease, indicating that the gas's internal energy has been decreased by doing work.

Answer:

space is three dimensional

Answer: Space is three-dimensional

Explanation: For Newton, space time forms a three-dimensional universe, with the characteristic of an absolute void that determines the order of the things that compose it.

The Heisenberg uncertainty principle was enunciated in 1927. It postulates that the fact that each particle has a wave associated with it, imposes restrictions on the ability to determine its position and speed at the same time.  

In other words:  

It is impossible to measure simultaneously (according to quantum physics), and with absolute precision, the value of the position and the momentum (linear momentum) of a particle.  

In fact, even with the most precise devices, the uncertainty in the measurement continues to exist. Thus, in general, the greater the precision in the measurement of one of these magnitudes, the greater the uncertainty in the measure of the other complementary variable.  

Therefore the correct option is C.

Light behaves like a wave, and the different colors we perceive are the result of light hitting our eyes at different wavelengths. The air molecules in our atmosphere scatter this visible light, with a "preference" towards light of shorter wavelengths -- blue and violet light. Light of longer wavelengths (green, yellow, orange, red), doesn't pass through to us as visibly until later in the day, when the sun's light has more atmosphere to pass through before it reaches our eyes. The blue light becomes so scattered by the air molecules in its way at this point that we're finally able to see those yellows and reds coming through on our end.

See the attached picture:

The correct answer is: C. It is the point beyond which neither light nor anything else can escape.

The event horizon of a black hole is the boundary where the escape velocity is equal to the speed of light, making it impossible for anything, including light, to escape. It's defined by the Schwarzschild radius and increases in size with additional mass. The center is thought to contain a singularity, which is infinitely dense and small.

The event horizon of a black hole is the boundary beyond which nothing, including light, can escape its gravitational pull. It corresponds to the distance at which the escape velocity equals the speed of light. This boundary is known as the Schwarzschild radius, which is directly proportional to the mass of the black hole. The event horizon is not visible because it does not emit any light; however, it can be inferred by observing the effects of its powerful gravity on nearby matter and radiation.

The size of the Schwarzschild radius (and therefore the event horizon) depends only on the mass of the black hole. If our Sun were to collapse into a black hole, which is purely a theoretical scenario since it lacks sufficient mass, its Schwarzschild radius would be approximately 3 kilometers. Any additional mass added to the black hole would increase the size of its event horizon proportionally.

Inside the event horizon, the center of the black hole is thought to contain a singularity, a point of infinite density and zero volume, which is not directly observable. As matter crosses the event horizon, it seems to freeze in position to an outside observer due to the extreme gravitational effects on lt's travel, but would, in reality, continue to fall inward toward the singularity.

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The photoelectric effect consists of the emission of electrons (electric current) that occurs when light falls on a metal surface under certain conditions.

If the light is a stream of photons and each of them has energy, this energy is able to pull an electron out of the crystalline lattice of the metal and communicate, in addition, a kinetic energy.

This is what Einstein proposed:  

Light behaves like a stream of particles called photons with an energy

[tex]E=h.f[/tex]  (1)

So, the energy [tex]E[/tex] of the incident photon must be equal to the sum of the Work function [tex]\Phi[/tex] of the metal and the kinetic energy [tex]K[/tex] of the photoelectron:

[tex]E=\Phi+K[/tex]  (2)

Where [tex]\Phi[/tex] is the minimum amount of energy required to induce the photoemission of electrons from the surface of a metal, and its value depends on the metal.

In the case of Copper [tex]\Phi=4.7eV[/tex]

Now, applying equation (2) in this problem:

[tex]E=4.7eV+1.10eV[/tex]  (3)

[tex]E=5.8eV[/tex]  (4)

Now, substituting (1) in (4):

[tex]h.f=5.8eV[/tex]  (5)

Where:

[tex]h=4.136(10)^{-15}eV.s[/tex] is the Planck constant  

[tex]f[/tex] is the frequency  

Now, the frequency has an inverse relation with the wavelength [tex]\lambda[/tex]:  

[tex]f=\frac{c}{\lambda}[/tex] (6)  

Where [tex]c=3(10)^{8}m/s[/tex] is the speed of light in vacuum  

Substituting (6) in (5):

[tex]\frac{hc}{\lambda}=5.8eV[/tex]   (7)

Then finding [tex]\lambda[/tex]:  

[tex]\lambda=\frac{hc}{5.8eV } [/tex]   (8)

[tex]\lambda=\frac{(4.136(10)^{-15} eV.s)(3(10)^{8}m/s)}{5.8eV }[/tex]    

We finally obtain the wavelength:

[tex]\lambda=213^{-9}m=213nm[/tex]    

The Nerve Tissue allows for coordination and control movement

Nervous tissue is used for coordination and control movement.

Explanation:

The group of organized cells that is in the nervous system, which is responsible in controlling the movements of the human body, sending and carrying signals to and from different body parts is called Nervous tissue.  It is also responsible in controlling functions in the body like digestion.

This tissue is classified into categories such as neurons and neroglia. The electric impulses are transmitted by neurons and supporting and protecting neurons is done by neuroglia. The whole nervous system is comprised of neurons.

(a) [tex]4.40\cdot 10^{20}N[/tex]

The distance between the Sun and the Earth is

[tex]d_{SE}=1.496 \cdot 10^11 m[/tex]

The distance between the Earth and the Moon is

[tex]d_{EM} = 3.84\cdot 10^8 m[/tex]

So, the distance between the Sun and the Moon, when the Moon is between the Earth and the Sun, is

[tex]d_SM = 1.496\cdot 10^{11}m -3.84\cdot 10^8 m=1.492\cdot 10^{11} m[/tex]

So the gravitational force between the Sun and the Moon is

[tex]F_{SM} = G \frac{M_S M_M}{d_{SM}^2}[/tex]

where

G is the gravitational constant

[tex]M_S = 1.988 \cdot 10^{30}kg[/tex] is the mass of the Sun

[tex]M_M = 7.384\cdot 10^{22}kg[/tex] is the mass of the Moon

[tex]d_{SM}=1.492\cdot 10^{11} m[/tex] is their distance

Substituting,

[tex]F_{SM} = (6.67\cdot 10^{-11}) \frac{(1.988\cdot 10^{30} kg)(7.384\cdot 10^{22}kg)}{(1.492\cdot 10^{11} m)^2}=4.40\cdot 10^{20}N[/tex]

(b) [tex]2.00\cdot 10^{20}N[/tex]

The gravitational force between the Earth and the Moon is

[tex]F_{EM} = G \frac{M_E M_M}{d_{EM}^2}[/tex]

where

G is the gravitational constant

[tex]M_E = 5.972 \cdot 10^{24}kg[/tex] is the mass of the Earth

[tex]M_M = 7.384\cdot 10^{22}kg[/tex] is the mass of the Moon

[tex]d_{EM}=3.84\cdot 10^{8} m[/tex] is their distance

Substituting,

[tex]F_{EM} = (6.67\cdot 10^{-11}) \frac{(5.972\cdot 10^{24} kg)(7.384\cdot 10^{22}kg)}{(3.84 \cdot 10^{8} m)^2}=2.00\cdot 10^{20}N[/tex]

(c) [tex]3.54\cdot 10^{22}N[/tex]

The gravitational force between the Earth and the Sun is

[tex]F_{ES} = G \frac{M_E M_S}{d_{ES}^2}[/tex]

where

G is the gravitational constant

[tex]M_E = 5.972 \cdot 10^{24}kg[/tex] is the mass of the Earth

[tex]M_S = 1.988 \cdot 10^{30}kg[/tex] is the mass of the Sun

[tex]d_{SE}=1.496 \cdot 10^{11} m[/tex] is their distance

Substituting,

[tex]F_{ES} = (6.67\cdot 10^{-11}) \frac{(5.972\cdot 10^{24} kg)(1.988\cdot 10^{30}kg)}{(1.496 \cdot 10^{11} m)^2}=3.54\cdot 10^{22}N[/tex]

To derive the force exerted by the Sun on the Moon the Earth on the Moon and the Sun on the Earth during a solar eclipse, you apply Newton's law of universal gravitation taking into account the respective masses of the Sun, Earth, and Moon as well as their distances from each other.

Determining the force exerted between celestial bodies during a solar eclipse involves understanding the gravitational relationship between them; primarily the gravitational forces between the Earth, Moon, and the Sun, and the principles of celestial mechanics.

Firstly, we know that the force of gravity follows Newton's law of universal gravitation: F = G (m1m2/r^2),where F is the force of gravity, m1 and m2 are the masses of the two bodies involved, r is the distance between the centers of the two bodies, and G is the gravitational constant.

For any of the specific forces asked in the question (i.e., the force exerted by the Sun on the Moon force exerted by the Earth on the Moon, and the force exerted by the Sun on the Earth), we would need specific values for the masses of the Sun, Earth, and Moon as well as their respective distances. Once those values are known, you can substitute into the above equation to obtain the force.

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According to Hubble  galaxies are classified into elliptical, spiral and irregular.

It should be noted this classification is based only on the visual appearance of the galaxy, and does not take into account other aspects, such as the rate of star formation or the activity of the galactic nucleus.  

The classification is as follows:  

1. Elliptical galaxies: Their main characteristic is that the concentration of stars decreases from the nucleus, which is small and very bright, towards its edges. In addition, they contain a large population of old stars, usually little gas and dust, and some newly formed stars.  

2. Spiral galaxies: They have the shape of flattened disks containing some old stars and also a large population of young stars, enough gas and dust, and molecular clouds that are the birthplace of the stars.  

3. Irregular Galaxies:  Galaxies that do not have well-defined structure and symmetry.  

In this context, galaxy M82 does not match with the first two types of galaxies, because it has not a defined shape.

Therefore, M82 is an  irregular galaxy.

Answer:

Multiple choice answer would be "None"

Explanation:

White dwarfs are radiating stored heat from earlier reactions.  

Technically, it would be the last fusion stage the star went through  

BEFORE it became a white dwarf, but that's nit-picking.

The energy source of a white dwarf is not a nuclear reaction in the traditional sense, but rather it is supported by a process called electron degeneracy pressure.

A white dwarf is the remnant of a low to medium-mass star (up to about 1.4 times the mass of the Sun) after it has exhausted its nuclear fuel. The core of the star collapses under gravity, and the electrons in the core become packed extremely closely together due to the Pauli exclusion principle, which states that no two electrons can occupy the same quantum state simultaneously.

This electron degeneracy pressure provides the counterforce to gravity, preventing further collapse. No nuclear reactions are occurring in a white dwarf as it no longer has the high temperatures and pressures required for nuclear fusion. Instead, it is a stellar remnant that is gradually cooling over time.

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Answer:

A 1.0 min

Explanation:

The half-life of a radioisotope is defined as the time it takes for the mass of the isotope to halve compared to the initial value.

From the graph in the problem, we see that the initial mass of the isotope at time t=0 is

[tex]m_0 = 50.0 g[/tex]

The half-life of the isotope is the time it takes for half the mass of the sample to decay, so it is the time t at which the mass will be halved:

[tex]m'=\frac{50.0 g}{2}=25.0 g[/tex]

We see that this occurs at t = 1.0 min, so the half-life of the isotope is exactly 1.0 min.

Answer:a

Explanation:test

Answer:

The electrical force is 9N

Explanation:

For point loads,  charged bodies very small compared to the distance r that separates them,  Coulomb discovered that the electric force is proportional to [tex]\frac{1}{r^{2}}[/tex]. So, if the distance is doubled, the force will decrease a [tex]\frac{1}{4}[/tex] of its initial value.

[tex]F=\frac{36N}{4}=9N[/tex]

When the distance between two charged objects is doubled, the electrostatic force between them becomes one-fourth of the original force. Thus, if the original force is 36 N, the new force would be 9 N.

The force between two charges is governed by Coulomb's Law, which states that the electrostatic force (F) between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance (r) between them. The law is mathematically expressed as F = k * (|q1*q2|) / r², where k is Coulomb's constant. If the distance between two charges is doubled, since the force is inversely proportional to the square of the distance, the new force will be one-fourth of the original force.

Thus, if the initial force is 36 N and the distance is doubled, the new force is calculated as:

Initial force: 36 N

New distance: 2r

New force (F') = F / (22) = 36 N / 4 = 9 N

Therefore, the new electrostatic force between the two objects when the distance is doubled would be 9 N.

The energy [tex]E[/tex] of a photon is given by the following formula:

[tex]E=h.f[/tex] (1)

Where:

[tex]h=4.136(10)^{-15}eV.s[/tex] is the Planck constant

[tex]f[/tex] is the frequency

Now, the frequency has an inverse relation with the wavelength [tex]\lambda[/tex]:

[tex]f=\frac{c}{\lambda}[/tex] (2)

Where [tex]c=3(10)^{8}m/s[/tex] is the speed of light in vacuum

Substituting (2) in (1):

[tex]E=\frac{hc}{\lambda}[/tex] (3)

Knowing this, let's begin with the answers:

For [tex]\lambda=50cm=0.5m[/tex]

[tex]E=\frac{(4.136(10)^{-15} eV.s)(3(10)^{8}m/s)}{0.5m}[/tex]  

[tex]E=\frac{1.24(10)^{-6}eV.m }{0.5m}[/tex]  

[tex]E=2.48(10)^{-6}eV[/tex]  

For [tex]\lambda=500nm=500(10)^{-9}m[/tex]

[tex]E=\frac{(4.136(10)^{-15} eV.s)(3(10)^{8}m/s)}{500(10)^{-9}m}[/tex]  

[tex]E=\frac{1.24(10)^{-6}eV.m }{500(10)^{-9}m}[/tex]  

[tex]E=2.48 eV[/tex]  

For [tex]\lambda=0.5nm=0.5(10)^{-9}m[/tex]

[tex]E=\frac{(4.136(10)^{-15} eV.s)(3(10)^{8}m/s)}{0.5(10)^{-9}m}[/tex]  

[tex]E=\frac{1.24(10)^{-6}eV.m }{0.5(10)^{-9}m}[/tex]  

[tex]E=2480 eV[/tex]  

As we can see, as the wavelength decreases, the energy increases.

Answer:

B) the blue one

Explanation:

We can assimilate each metal bar to a black body. The peak wavelength of the radiation emitted by a blackbody is given by Wien's displacement law:

[tex]\lambda = \frac{b}{T}[/tex] (1)

where

b is the Wien's displacement constant

T is the absolute temperature of the object

In this case, we have one object hotter and the other one colder. We see from (1) that the peak wavelength is inversely proportional to the temperature: therefore, the hotter object will have shorter peak wavelength, while the colder object will have longer peak wavelength.

Since red light has longer wavelength than blue light, we can conclude that the object that glows blue is hotter than the one that glows red.

Answer:

Explanation:

There are 12 gtts in 1 mL, and 60 minutes in 1 hr.

250 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 50 gtts/min

167 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 33.4 gtts/min

125 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 25 gtts/min

75 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 15 gtts/min

1000 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 200 gtts/min

500 mL/hr * (12 gtts / mL) * (1 hr / 60 min) = 100 gtts/min

physical:1.Hydrogen is a colorless,tasteless and odourless gas.2.Hydrogen is the least dense of all elements.

chemical:1.hydrogen is very combustible in the presence of oxygen.2.hydrogen is very reactive with most elements.

Answer: Hydrogen is a colorless, tasteless, and odorless gas : Physical property

Hydrogen is very combustible in the presence of oxygen: Chemical property

Hydrogen is very reactive with most elements :  Chemical property

Hydrogen is the least dense of all elements:  Physical property

Explanation:

Chemical property is defined as the property of a substance which is observed during a reaction where the chemical composition identity of the substance gets changed.

Physical property is defined as the property which can be measured and whose value describes the state of physical system. For Example: State, density etc.

Hydrogen is a colorless, tasteless, and odorless gas  is a physical property.

Hydrogen is very combustible in the presence of oxygen is a chemical property.

Hydrogen is very reactive with most elements is a chemical property.

Hydrogen is the least dense of all elements is a physical property.

Explanation:

that don't look bright

Answer:

0.46 J/gC

Explanation:

The specific heat capacity of a material is given by:

[tex]C_s = \frac{Q}{m \Delta T}[/tex]

where

Q is the amount of heat absorbed

m is the mass

[tex]\Delta T[/tex] is the variation of temperature

For the piece of iron in the problem:

[tex]m = 15.75 g[/tex]

[tex]Q=1086.75 J[/tex]

[tex]\Delta T=175 C-25 C=150^{\circ}[/tex]

Substituting into the equation,

[tex]C_s = \frac{1086.75 J}{(15.75 g)(150^{\circ}C)}=0.46 J/gC[/tex]

Answer:

0.46 J/gC

Explanation:

The specific heat capacity of a material is given by:

where

Q is the amount of heat absorbed

m is the mass

is the variation of temperature

For the piece of iron in the problem:

Substituting into the equation,

Explanation:

Vector A has the greater x-component, while vector B has the greater y-component.

The x-component of a vector can be calculated by multiplying its magnitude by the cosine of the angle it makes with the x-axis. For vector A, the x-component is 50 units (since it lies entirely on the x-axis). For vector B, the x-component equals 120 units * cos(70 degrees) = 40.96 units. So, vector A has the greater x-component.

The y-component of a vector can be calculated by multiplying its magnitude by the sine of the angle it makes with the x-axis. For vector A, the y-component is 0 (since it lies completely on the x-axis). For vector B, the y-component equals 120 units * sin(70 degrees) = 112.90 units. So, vector B has the greater y-component.

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Answer:inner core?

Explanation:

Answer: your answer would be inner core hope it helps

Explanation:

tell me i am wrong?

Answer:

B they are all radio waves with frequencies lower than visible light

Explanation:

The electromagnetic spectrum classifies all the electromagnetic waves according to their frequency. In order from highest to lowest frequency, we have:

Gamma rays

X-rays

Ultraviolet

Visible light

Infrared

Microwaves

Radio waves

In particular, radio waves are the electromagnetic waves with lowest frequency (and longest wavelength), usually less than 300 GHz ([tex]300\cdot 10^9 Hz[/tex]).

Microwaves radar, radio waves and television waves are all examples of radio waves, which have frequencies lower than visible light. Radio waves are generally used for long-range communications, because given their long wavelength they are able to "bypass" huge obstacles like mountains or building, without being absorbed.

Answer:

B they are all radio waves with frequencies lower than visible light

Explanation:

Answer:

It is most likely the word elliptical.

Explanation:

Usually the term elliptical refers to the oval-like shape of a substance or path of an object.  The question states, "Planets in our solar system do not revolve around the sun in perfect circles. Their orbits are more like ovals."  Because the planets orbit around the sun in an oval-like path, those orbits can be described as elliptical.  Scientists also normally use this word to describe the same thing; Therefore, your answer is elliptical.

Planets in our solar system do not revolve around the sun in perfect circles. They revolve in the elliptical orbits.

The solar system consists of the planet's satellites, as well as numerous comets, asteroids, and meteoroids, as well as the interplanetary medium.

Planets in our solar system do not revolve around the sun in perfect circles. They revolve in the elliptical orbits.

Hence, option D is correct.

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Answer:

formed in the middle of a plate

formed where mantle erupts through crust

Explanation:

The Hawaiian Islands are Volcanoes that formed right in the middle of the Pacific plate which is moving North-westward.

Lithospheric plates lies on the weak and plastic asthenosphere. Such is the Pacific plate too. The weak asthenosphere can erupt on the surface if it gets access through faulting or other geologic conduits. When these mantle magma reaches the surface, they form hotpots on the crust.

The Hawaiian island is a series of these hotspot as it forms when mantle materials upwells to the surface. The hotspot from which the magma is sourced is relatively fixed. The moving plate is what leads to the eruption of the magma at several other parts in the crust.

answer:

1.8E-15C/1.6E-19=11,250

Explanation:

The biochemistry that takes place inside cells depends on various elements, such as sodium, potassium, and calcium, that are dissolved in water as ions. These ions enter cells through narrow pores in the cell membrane known as ion channels. Each ion channel, which is formed from a specialized protein molecule, is selective for one type of ion. Measurements with microelectrodes have shown that a 0.30-nm-diameter potassium ion ({\rm{{\rm K}}}^{\rm{ + }} ) channel carries a current of 1.8 {\rm pA}.

The number of potassium ions that will pass through the ion channel is 11250.

Potassium ions, possibly the most often constituted electrolyte.

Calculating the number of potassium ions that passes through the ion channel

Given that the channel opens for 1.0 ms

Step1: determine the value of charge ( Q )

[tex]Q = I \times \Delta t = ( 1.8 \times 10^-^1^0 A )\times (1.0 \times 10^1^3 s ) = 1.8 \times 10^-^1^5 C[/tex]

where ; I = 1.8 × 10⁻¹² A

[tex]\Delta t = 1.0 \times 10^-^3 s[/tex]

Step2: determine number of K⁺ ions passing through

[tex]NK^+ = Q \times e = ( 1.8 \times 10^-^1^5 C )\times ( 1.60 \times 10^-^1^9 C) = 11250[/tex]

Thus, the potassium ions pass through the channel is 11250.

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Answer:

2, 4, 5

Explanation:

The electromagnetic spectrum gives the classification of the electromagnetic waves according to their wavelength/frequency. In order from the shortest to the greatest wavelength, we have:

Gamma rays

X-rays

Ultraviolet

Visible light

Infrared

Microwaves

Radio waves

Moreover, the frequency of an electromagnetic wave is inversely proportional to its wavelength, according to:

[tex]f=\frac{c}{\lambda}[/tex]

where c is the speed of light.

Finally, the energy of a photon of an electromagnetic wave is directly proportional to the frequency, and inversely proportional to the wavelength:

[tex]E=hf = \frac{hc}{\lambda}[/tex]

where h is the Planck constant.

Keeping in mind these facts, let's now analyze each statement:

1. X rays and gamma rays have very long wavelengths and very low photon energies. --> FALSE: X-rays and gamma rays have the shortest wavelength, so they have the highest frequency and very high energy.

2. Radio waves have wavelengths on the order of meters and very low photon energies. --> TRUE. Radio wave wavelengths are on the order of meters, so very long; consequently, their frequency is very low, and so their energy is also very low.

3. Ultraviolet radiation has long wavelengths and low photon energies. --> FALSE. Ultraviolet has short wavelength, so high frequency and high photon energy.

4. Visible light lies at the center of the electromagnetic spectrum. --> TRUE: visible light photons have wavelength between 380 and 750 nm, and lie at the center of the electromagnetic spectrum.

5. Infrared radiation has long wavelengths and low photon energies. --> TRUE: infrared radiation has longer wavelengths (if compared to the visible light), and therefore lower frequency and lower energy.

X-rays and gamma rays have high photon energies and short wavelengths, radio waves have long wavelengths and low photon energies, visible light lies in the middle of the electromagnetic spectrum.

Among the statements, the correct ones regarding the electromagnetic spectrum are:

Based on the information about the characteristics and properties of electromagnetic radiation, these statements accurately reflect the nature of X-rays, gamma rays, radio waves, and visible light.

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Answer:

Explanation:

[tex] 30W * 8 h = 240 Wh = 0.240 kWh[/tex]

Answer:

0.24 kWh

Explanation:

To increase the power factor to 1.0 in a motor circuit, a capacitor should be added. The capacitance value of the capacitor can be calculated by knowing the real and apparent power of the motor circuit before and after the capacitor addition. The introduction of the capacitor provides reactive power that neutralizes the inductiveness of the motor coil, making the circuit purely resistive.

The subject matter pertains to understanding power factor, power dissipation and the effects of adding capacitance in a motor circuit. Now, the question mentions that the motor draws 8.40 A current at 120 V giving us a power apparent = V*I = 120 * 8.40 VA. However, the average power dissipated (Real power, P) is 850 W. The power factor is the ratio of real power to apparent power. However, to achieve a power factor of 1 (i.e., make the circuit purely resistive), we must add a capacitor (reactive power component) that will counteract the inductiveness of the motor coil.

The power factor before the capacitor is added is P/S = 850/(120*8.4) =  0.84. The reactive power Q before the capacitor is added can be calculated by the formula Q = sqrt[(S^2)-(P^2)] = sqrt[((120*8.4)^2)-(850^2)] VAR. After the capacitor is added, the power factor is 1 (as per the question), which means the reactive power Q' = 0. Therefore, reactive power supplied by the capacitor C = Q - Q' = Q = sqrt[((120*8.4)^2)-(850^2)].

Using Q = sqrt[(S^2)-(P^2)], we can find the current supplied by the capacitor as Ic = Q/V. From this current, we can find the capacitance using the formula C = Ic / (2*π*f.*V) where f = frequency = 60 Hz.

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To improve the power factor of a 120 V motor that draws 8.40 A to unity, we need to add a 94.6 µF series capacitance. This helps cancel out the reactive power, thereby achieving a power factor of 1.0.

Calculating Series Capacitance to Improve Power Factor

To increase the power factor to 1.0 for a motor attached to a 120 V/60 Hz power line that draws an 8.40 A current and has an average energy dissipation of 850 W, follow these steps:

Step 1: Calculate Apparent Power (S)

we know , Apparent power S = V * I

Where:

V = 120 V

I = 8.40 A

So,

S = 120 V * 8.40 A = 1008 VA

Step 2: Calculate the Current Power Factor (pf)

The power factor is the ratio of real power (P) to apparent power (S). Therefore:

pf = P / S = 850 W / 1008 VA ≈ 0.843

Step 3: Calculate the Reactive Power (Q)

Reactive power can be determined using the Pythagorean theorem for the power triangle:

Q = √(S² - P²)

So,

Q = √(1008² - 850²) ≈ 512 VAR

Step 4: Calculate Required Capacitive Reactance (Xc)

For unity power factor, the reactive power provided by the capacitor should cancel out the Q value:

Xc = V² / Q

So,

Xc = 120² / 512 ≈ 28.125 ohms

Step 5: Calculate Series Capacitance (C)

Use the formula for capacitive reactance:

Xc = 1 / (2πfC)

Solve for C:

C = 1 / (2π * 60 Hz * 28.125 ohms) ≈ 94.6 µF

Adding a series capacitance of approximately 94.6 µF will increase the power factor to 1.0.