A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is A) zero. B) equal to its weight divided by its mass. C) equal to the product of its mass times its weight.

During convection of air currents,  cool air sinks. (b)

Answer:

Cool air sinks

Explanation:

In this type of heat transfer, warm air rises and cool air sinks, making a current. Which is convection

Answer:

B

Explanation:

E = hf

E = (6.626×10⁻³⁴ Js) (8.0×10¹⁵ 1/s)

E = 5.3×10⁻¹⁸ J

Answer is B.

Answer:

yes answer is B

Explanation:

Answer:

No

Explanation:

Let's assume the gas pressure is constant. Then we can use Charle's law, which states that the volume of the gas is proportional to the absolute temperature (in Kelvin):

[tex]\frac{V}{T}=const.[/tex]

This can be rewritten as

[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]

where we have

[tex]T_1 = 100^{\circ}+273 =373 K[/tex]  is the initial temperature of the gas

[tex]T_2 = 50^{\circ}+273 =323 K[/tex]  is the final temperature of the gas

Re-arranging the previous equation, we find

[tex]V_2=V_1 \frac{T_2}{T_1}=V_1 \frac{323 K}{373 K}=0.87 V_1[/tex]

so, the volume of the gas decreases by a factor 0.87.

Answer:

Insurance is for items like cars and things health insurance is for injuries. Hope this helps!

Explanation:

Answer:

Increasing the area of the plates will increase the capacitance of a parallel-plate capacitor.

Decreasing the separation between the plates will increase the capacitance of a parallel-plate capacitor.

Explanation:

The capacitance of a parallel-plate capacitor is given by

[tex]C=\frac{\epsilon_0 A}{d}[/tex]

where

[tex]\epsilon_0[/tex] is the vacuum permittivity

A is the area of the plates

d is the separation between the plates

We notice that:

- The capacitance is directly proportional to A, the area of the plates

- The capacitance is inversely proportional to d, the separation between the plates

Therefore, the correct statements are:

Increasing the area of the plates will increase the capacitance of a parallel-plate capacitor.

Decreasing the separation between the plates will increase the capacitance of a parallel-plate capacitor.

Answer:

It is NOT C. It is directly proportional, so the capacitance decreases as the distance increases.

Explanation:

(a) -15.2 cm

We can solve the problem by using the lens equation:

[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}[/tex]

where

f = -22.8 cm is the focal length of the lens (negative because it is a diverging lens)

p = 45.6 cm is the distance of the object from the lens

q is the distance of the image from the lens

Solving the equation for q, we find the position of the image:

[tex]\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{-22.8 cm}-\frac{1}{45.6 cm}=-0.066 cm^{-1}[/tex]

[tex]q=\frac{1}{-0.066 cm^{-1}}=-15.2 cm[/tex]

and the negative sign means that the image is virtual.

(b) -11.4 cm

In this case, the distance of the object from the lens is

p = 22.8 cm

Substituting into the lens equation, we can find the new image distance, q:

[tex]\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{-22.8 cm}-\frac{1}{22.8 cm}=-\frac{2}{22.8 cm}[/tex]

[tex]q=\frac{-22.8 cm}{2}=-11.4 cm[/tex]

and the negative sign means that the image is virtual.

(c) -7.6 cm

In this case, the distance of the object from the lens is

p = 11.4 cm

Substituting into the lens equation, we can find the new image distance, q:

[tex]\frac{1}{q}=\frac{1}{f}-\frac{1}{p}=\frac{1}{-22.8 cm}-\frac{1}{11.4 cm}=-0.132 cm^{-1}[/tex]

[tex]q=\frac{1}{0.132 cm^{-1}}=-7.6 cm[/tex]

and again, the negative sign means that the image is virtual.

Final answer:

To locate the images for a diverging lens with a focal length of -22.8 cm, the lens formula is used, yielding image distances of approximately -45.6 cm for an object 45.6 cm away, undefined (at infinity) for an object 22.8 cm away, and -15.2 cm for an object 11.4 cm away.

Explanation:

To locate the images formed by a diverging lens with a negative focal length, we use the lens formula:

[tex]\( \frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} \)[/tex]

Where  f is the focal length, [tex]\( d_o \)[/tex] is the object distance, and [tex]\( d_i \)[/tex] is the image distance. Since the lens is diverging, f  is negative.

Given a focal length (f) of -22.8 cm for the diverging lens, we can solve for the image distance [tex](\( d_i \))[/tex] for the following object distances [tex](\( d_o \))[/tex] :

The negative sign for [tex]\( d_i \)[/tex] means that the image is virtual and located on the same side as the object.

A) [tex]5.34\cdot 10^5 m/s[/tex]

The minimum speed of the electron occurs when the electron loses the maximum energy: this occurs when the electron excites the atom from 0.0 eV to 4.0 eV, because in this case the energy given to the atom is maximum.

The energy given by the electron to the atom is equal to the difference between the two energy levels:

[tex]\Delta E= 0.0 eV - 4.0 eV =-4.0 eV = -6.4\cdot 10^{-19}J[/tex]

This is equal to the kinetic energy lost by the electron:

[tex]K_f - K_ i = \Delta E\\\frac{1}{2}m(v^2-u^2) = \Delta E[/tex]

where

m is the electron's mass

v is the final speed of the electron after the collision

[tex]u=1.3\cdot 10^6 m/s[/tex] is the speed of the electron before the collision

Solving for v, we find

[tex]v=\sqrt{ \frac{2\Delta E}{m}+u^2}=\sqrt{\frac{2 (-6.4\cdot 10^{-19} J)}{9.11\cdot 10^{-31} kg}+(1.3\cdot 10^6 m/s)^2}=5.34\cdot 10^5 m/s[/tex]

B) [tex]1.16\cdot 10^6 m/s[/tex]

The maximum speed of the electron occurs when the electron loses the minimum amount of energy: this occurs when the electron excites the atom from 3.0 eV to 4.0 eV, because in this case the energy given to the atom is minimum.

The energy given by the electron to the atom is equal to the difference between the two energy levels, so in this case we have:

[tex]\Delta E= 3.0 eV - 4.0 eV =-1.0 eV = -1.6\cdot 10^{-19}J[/tex]

And so, this time the final speed of the electron after the collision will be given by:

[tex]v=\sqrt{ \frac{2\Delta E}{m}+u^2}=\sqrt{\frac{2 (-1.6\cdot 10^{-19} J)}{9.11\cdot 10^{-31} kg}+(1.3\cdot 10^6 m/s)^2}=1.16\cdot 10^6 m/s[/tex]

The minimum speed the electron could have after collision is 6.62x10^7 m/s, and the maximum speed is 2.96x10^7 m/s.

The electron can gain energy by absorbing a photon with an energy equal to the difference between the final and initial energy states of the atom. The minimum speed is reached when the electron absorbs the photon with the smallest energy, which corresponds to the energy difference between the initial and first excited state of the atom.

The energy spacing between the lowest energy state (0.0 eV) and the first excited state (3.0 eV) is 3.0 eV. Converting this energy to joules, we get 4.8 x 10^(-19) J. Using the equation E = 1/2 mv^2, we can calculate the minimum speed by solving for v:

v = √(2E/m)

where E is the energy change (4.8 x 10^(-19) J) and m is the mass of the electron (9.11 x 10^(-31) kg). Plugging in the values, we find v = 6.62 x 10^7 m/s.

The energy spacing between the lowest energy state (0.0 eV) and the second excited state (4.0 eV) is 4.0 eV, which is equivalent to 6.4 x 10^(-19) J. Using the same equation, we can calculate the maximum speed:

v = √(2E/m)

where E is the energy change (6.4 x 10^(-19) J) and m is the mass of the electron (9.11 x 10^(-31) kg). Plugging in the values, we find v = 2.96 x 10^7 m/s.

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Answer:

9 ft/s²

Explanation:

1)

d²s/dt² = -k

Integrate once:

ds/dt = -kt + C

At t=0, ds/dt = 66:

66 = -k(0) + C

C = 66

ds/dt = -kt + 66

Integrate again:

s = -½ kt² + 66t + D

At t=0, s = 0:

0 = -½ k (0)² + 66 (0) + D

D = 0

s = -½ kt² + 66t

2)

Setting ds/dt = 0:

0 = -kt + 66

t = 66/k

3)

Setting s = 242:

242 = -½ kt² + 66t

242 = -½ k (66/k)² + 66 (66/k)

242 = -2178/k + 4356/k

242 = 2178/k

k = 9

The driver must decelerate at 9 ft/s².

Final answer:

Doubling the frequency of an AC source connected to a capacitor halves the capacitive reactance due to the inverse relationship between frequency and capacitive reactance.

Explanation:

The question seems to contain a slight error in terminology, implying a mix-up between capacitive and inductive components. However, addressing the core intent, if a capacitor is connected across an AC source and the frequency of the source is doubled, the capacitive reactance is reduced by a factor of 2. This outcome is based on the principle that capacitive reactance (XC) is inversely proportional to both the frequency of the AC source (f) and the capacitance (C). The formula for capacitive reactance is XC = 1/ (2πfC), indicating that as the frequency (f) increases, XC decreases. Therefore, doubling the frequency results in the halving of the capacitive reactance, making the correct answer 'The capacitive reactance is reduced by a factor of 2'.

The nuclear fission consists of dividing a heavy nucleus into two or more lighter or smaller nuclei, by means of the bombardment with neutrons to make it unstable.

Then, with this division a great release of energy occurs and the emission of two or three neutrons, other particles and gamma rays.

It should be noted that in the process, the emitted neutrons can interact with new fissionable nuclei that will emit new neutrons and so on. Effect better known as chain reaction.

Nuclear fission is the process of splitting heavy atomic nuclei into smaller ones, releasing energy due to the mass difference. It can produce a chain reaction that is critical for nuclear power plants and nuclear weapons.

Nuclear fission is the process of creating energy by splitting heavy atomic nuclei into smaller, medium-mass nuclei. This occurs when a neutron collides with a nucleus causing it to split into two isotopes. The mass of the products is less than the mass of the reactants, and the difference in mass is released as a tremendous amount of energy. A notable characteristic of fission is the release of additional neutrons, which can induce further fissions, leading to a chain reaction. This principle is harnessed in both nuclear power plants and nuclear weapons. To sustain a chain reaction, a certain amount, known as the critical mass, is required. The reaction can be represented as: n+AX → FF₁ + FF2 + xn, where FF₁ and FF₂ are the fission fragments, and x is the number of neutrons produced.

Answer:

-3.4 eV ([tex]-5.4\cdot 10^{-19} J[/tex])

Explanation:

In a hydrogen atom, the energy of an electron is given by:

[tex]E_n = - 13.6 eV \frac{1}{n^2}[/tex]

where

n is the principal quantum number

For an electron in the 2s orbital,

n = 2

So substituting this value into the formula, we find

[tex]E_2 = -13.6 eV \frac{1}{2^2}=-3.4 eV[/tex]

And converting this into Joules, we have

[tex]E_2 = -3.4 eV \cdot 1.6\cdot 10^{-19} J/eV=-5.4\cdot 10^{-19} J[/tex]

Answer:

This is because the microwave oven heats the food by heating the water molecules that compose it.

This is achieved by increasing the vibration amplitude of the water molecules and their kinetic energy, therefore, increasing their temperature.

So, if the element that gets into the microwave oven does not contain water (as is the case of an empty paper plate), it will not heat up.

In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions

Answer:

Metals possess low ionisation energy hence it loses electrons easily. The nucleus and the inner shell electrons is called the kernel.

The electron which gets lost leaves the influence of one kernel and moves towards the other.

Thus the electrons will be in constant movement and gets delocalized.

The electrostatic forces between the positive kernel and the sea of mobile electrons is called as metallic bond.

Metal atoms possess this type of attractive forces in between them.

For example the metal atoms of a sheet of copper possess this type of chemical bond between the atoms.

Thus, Metallic bonding is a type of chemical bonding that rises from the electrostatic attractive force between conduction electrons and positively charged metal ions

Answer:

About 4-10cm/yr

Explanation:

Plates have different motion due to the tectonic settings and the properties of the plates.

Tectonic plates typically move very slowly over the weak asthenosphere in the mantle. This accounts for the wide range of about 4-10cm/yr. Some plates moves slower than this. It is difficult to perceive plate movement using our observational senses.

Scientists use GPS units and satellites to monitor the rate of movement of plates in a year to as to forecast a whole lot of environmental event that might  result from that.

Answer:

192 mm/s

Explanation:

The frequency, speed  and wavelength  of any given wave are related to one another by the formula;

fλ = v

Where f denotes the frequency, v the speed or velocity and λ the wavelength

We are given that;

λ = 12

f = 16

v = 16 * 12 = 192 mm/s

Answer

Human activity is impacting biodiversity.

Explanation:

Human activity is impacting because due to overpopulation and poverty we are changing our life style which have negative impact on climate.

Answer:

Explanation:

Biodiversity can be define as the variability of life on planet earth. It typically measures the variations in terms of types of species, ecosystem levels and genetic variations. The terrestrial biodiversity is typically greater near the equator which is because of high primary productivity and warm climatic conditions.

The human activities impact the biodiversity by occupying the area where the natural biodiversity sustains like forests, grasslands and others. Other activities like hunting, poaching and wildlife trafficking can lead to the extinction of many wildlife species. The plants and trees are removed for their wood, medicine and for other needs this has lead to the decrease in abundance of valuable floral species.

The hypothesis is; A cat's heart rate changes while it is napping.

A hypothesis is a tentative statement which could be proved or disproved by subjecting it to rigorous experimentation.

A hypothesis is coined in line with the question that the experiment seeks to answer.

In this case, Fatima's question is; Does a cat's heart rate changes while it is napping?

So the hypothesis must be;  A cat's heart rate changes while it is napping.

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Answer:

[tex]6.4\cdot 10^{-15} N[/tex]

Explanation:

The electric force exerted on the electron is given by:

[tex]F=qE[/tex]

where

[tex]q=1.6\cdot 10^{-19}C[/tex] is the magnitude of the electron charge

E = 40000 V/m is the electric field

Substituting,

[tex]F=(1.6\cdot 10^{-19} C)(40000 V/m)=6.4\cdot 10^{-15} N[/tex]

By comparison, the gravitational force exerted on the electron is:

[tex]F=mg[/tex]

where

[tex]m=9.10939\cdot 10^{-31} kg[/tex] is the mass of the electron

g = 9.8 m/s^2 is the acceleration due to gravity

Substituting,

[tex]F=(9.10939\cdot 10^{-31} kg)(9.8 m/s^2)=8.93\cdot 10^{-30}N[/tex]

Final answer:

The force exerted on an electron by a 40000 V/m electric field is 6.408 × 10−15 N, which is significantly greater than the gravitational force on the electron (8.927 × 10−30 N). Therefore, gravitational forces on electrons are commonly neglected in physics.

Explanation:

The force exerted on an electron by an electric field can be calculated using the equation F = qE, where q is the charge of the electron and E is the electric field strength. Given the charge of the electron q = 1.602 × 10−19 C and the electric field strength E = 40000 V/m, we can calculate the force as:

F = (1.602 × 10−19 C) × (40000 V/m) = 6.408 × 10−15 N.

This force is much larger compared to the gravitational force on an electron, which is calculated by F = mg, where m is the mass of the electron and g is the acceleration due to gravity (9.8 m/s2). The mass of the electron m = 9.10939 × 10−31 kg, hence the gravitational force is:

F_gravity = (9.10939 × 10−31 kg) × (9.8 m/s2) ≈ 8.927 × 10−30 N.

The comparison between the electric force and gravitational force on an electron clearly shows that the electric force is significantly stronger, which is why gravitational forces on electrons are often neglected in physics calculations involving electric fields.

The energy transferred between objects with different temperatures is

Thermal energy

Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy.

Thermal energy get transfer from higher to lower temperature object in order to maintain equilibrium .

Thermal energy transfers occur in three ways: through conduction, convection, and radiation

The energy transferred between objects with different temperatures is

Thermal energy

learn more about Thermal energy

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Heat is the energy transferred between two objects at different temperatures until they reach the same temperature. This spontaneous energy transfer is driven by the temperature difference and does not involve work, as there is no force acting through a distance.

The energy transferred between objects with different temperatures is known as heat. When two objects at different temperatures are in contact, energy flows from the hotter object to the colder one until they reach thermal equilibrium—that is, they are at the same temperature. This transfer of energy is a spontaneous process and occurs due to the difference in temperature.

Internal energy plays a role in this process; an object with a higher temperature has higher internal energy. When energy transfers, there is no work done because no force is acting through a distance. The presence of a temperature difference is what drives the energy transfer, and once the temperatures equalize, this energy transfer ceases.

Heat is one of the ways through which a system's total energy can change, as per Enduring Understanding 4.C of interactions with systems. This is a fundamental concept in the study of thermodynamics and an essential part of understanding how energy moves within the universe.

Answer:

the speed of particles decreases as the states of matter change. to support: in a solid, the speed of particles is slow. in a liquid, the speed of particles is mediocre. and in a gas, the speed of particles is fast since they are spread out.

:) have a nice day love ❤

Explanation:

Answer:

On the magnitude of the charges, on their separation and on the sign of the charges

Explanation:

The magnitude of the electric force between two charges is given by

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

where

k is the Coulomb's constant

q1, q2 are the magnitudes of the two charges

r is the separation between the charges

From the formula, we see that the magnitude of the force depends on the following factors:

- magnitude of the two charges

- separation between the charges

Moreover, the direction of the force depends on the sign of the two charges. In fact:

- if the two charges have same sign, the force is repulsive

- if the two charges have opposite signs, the force is attractive

Answer:

[tex]\Delta E = -5.89\cdot 10^{-19} J[/tex]

Explanation:

The change in energy of the electron that undergoes the decay is equal to the energy of the photon, which is given by:

[tex]\Delta E=hf[/tex]

where

h is the Planck constant

f is the frequency of the Photon

Here we have

[tex]f=8.88\cdot 10^{14}Hz[/tex]

Substituting into the formula, we find

[tex]\Delta E=(6.63\cdot 10^{-34} Js)(8.88\cdot 10^{14}Hz)=5.89\cdot 10^{-19} J[/tex]

and since the electron decays from a higher energy level to the ground state, its change in energy will be negative:

[tex]\Delta E = -5.89\cdot 10^{-19} J[/tex]

The change in energy ΔE, that an electron undergoes when it decays to its ground state during triboluminescence can be calculated using the energy of a photon formula E=hf. By substituting the given values, we get E=(6.63 x 10^-34 JS) x (8.88 x 10^14 Hz), which results in E=5.89 x 10^-19 Joules.

In the phenomenon of triboluminescence, the change in energy denoted by ΔE that an electron undergoes to decay to its ground state can be found using the formula for the energy of a photon: E = hf, where h is Planck's constant (6.63 x 10^-34 Joule seconds) and f is the frequency of the photon. Given that the frequency of the photon emitted when the decay occurs is 8.88 x 10^14 Hz, we multiply this frequency by Planck's constant to find the change in energy.

E = hf = (6.63 x 10^-34 JS) x (8.88 x 10^14 Hz) = 5.89 x 10^-19 Joules. This value is the change in energy that the electron undergoes as it decays to its ground state, a phenomenon evidenced by the sparks observed when wintergreen candies are chewed.

Triboluminescence, while intriguing and visible in the dark, is the result of energetic electrons reacting with nitrogen molecules and releasing energy in the form of visible light. This physical phenomenon can be explained and calculated using basic principles of photon energy.

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Answer:

B

Explanation:

Judging from the shape of the lens, you already know that the lenses are concave rather than convex. This eliminates C and D. Concave lens produce a smaller and virtual image at any specified distance.

Hope this helped!

Answer:

2 times

Explanation:

1st time on Feb. 20, 1962 at age 41

2nd time on Oct. 29, 1998 at age 77

Answer:

first is Diffraction and is when waves spread out because of going through a narrow gap

second is Refraction literally stole that image off the internet when waves deflect traveling through different density

third reflection when waves bounce off a surface without them being absorbed

Answer:

1.when a light ray bends around corners it's called (3.)Diffraction

2.when a light bounces off a surface it is called a (1.) reflection

3.when a light ray changes direction as it enters a new medium this is called (2.)refraction

Answer:

0 J

Explanation:

Kinetic energy is defined as:

KE = 1/2 m v²

where m is mass and v is velocity.

The car starts at rest, so it has zero velocity.  Therefore, its initial kinetic energy is 0 J.

Answer:

A

Explanation:

This is why we use halogen lightbulbs for lighting at homes. They produce visible spectrum of electromagnetic waves hence allowing us to perceive through sight in the dark. The tungsten in the bulb heat ups through electrical resistance that causes it to emit heat energy. The heat causes electrons to escape from the filament forming visible light.

ultra violet disinfecting wand

Answer:

On balance, near the equator, but I would say it really depends on the environment you were looking in. On land, relatively little lives near the south pole as it is an ice sheet, and there is no land at the north pole. Marine environments are less clear cut. Tropical reefs have high biodiversity (probably more so than any other marine environment), but generally everywhere life is sparser in the deep ocean. Some polar marine environments also contain abundant life though as the cold increases oxygen solubility in the water and also means most organisms have a slow metabolism. Glacial activity grinding up rocks also means polar water can have more available nutrients.

Greater biodiversity is found near the equator.

One would expect to find greater biodiversity near the equator compared to Earth's poles. This phenomenon, recognized as one of the oldest patterns in ecology, demonstrates that biodiversity significantly increases as latitude declines. Near the equator, especially in tropical rainforests, the species richness is the highest. In contrast, near the poles, the species richness markedly decreases due to factors like lower temperatures, which limit year-round growth and reduce the number and complexity of available ecological niches.

Several hypotheses have been proposed to explain why biodiversity is greater near the equator. These include the greater age of tropical ecosystems, which allows more time for speciation; the higher energy input from the sun; the complexity of tropical ecosystems providing a wider variety of ecological niches; and the relative stability of the climate in tropical regions promoting speciation. Regardless of the specific mechanisms, it's clear that the equator hosts a much richer biodiversity compared to the poles.

I think this is TRUE. Ph is calculating the acidic acids in water. And you need to know the concentration of hydronium ions. Hope this helped !

Answer:

5.03 m

Explanation:

The wavelength of a wave is given by

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

where

v is the speed of the wave

f is the frequency of the wave

For the sonar signal in this problem,

[tex]f=288 Hz[/tex]

[tex]v=1.45\cdot 10^3 m/s[/tex]

Substituting into the equation, we find the wavelength:

[tex]\lambda=\frac{1.45\cdot 10^3 m/s}{288 Hz}=5.03 m[/tex]

Taking into account the definition of wavelength, frecuency and propagation speed, the correct answer is the third option: The wavelength of the sonar signal is 5.03 m.

In first place, wavelength (λ) is one of the parameters used to physically define a wave. This parameter can be defined for any periodic wave, that is, for the type of wave that repeats itself with exactly the same shape every given interval of time.

In a periodic wave the wavelength is the physical distance between two points from which the wave repeats itself. It is expressed in units of length (m).

On the other side, frequency (f) is the number of vibrations that occur in a unit of time, that is, a measure of the number of cycles or repetitions of the wave per unit of time. Its unit is s⁻¹ or hertz (Hz).

Finally, the propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement.

Relate the wavelength and the frequency inversely proportional using the following equation:

v = f × λ

In this case, you know:

Replacing:

1.45×10³ m/s= 288 Hz× λ

Solving:

λ= 1.45×10³ m/s÷ 288 Hz

λ= 5.03 m

Finally, the correct answer is the third option: The wavelength of the sonar signal is 5.03 m.

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