At the point 0, there are 2 point sources, emitting the same constant sound power,
with intensity in inversely proportional to the square of the distance from the source. At the point A, the sound level intensity is [tex]20dB[/tex]
(a) What is the sound level intensity at A of one source?
(b) What is the number of sources that we have to add at A so that the sound level intensity at the midpoint M of OA is [tex]30dB[/tex]?

(a) The final velocity of the blue ball is 5 m/s after the collision

(b)  The final velocity of the blue ball is 6 m/s after the collision.

To solve this problem, we can use the conservation of momentum and the conservation of kinetic energy. The total momentum and total kinetic energy of the system before and after the collision must be the same.

a. When the green ball stops moving after the collision, its final velocity is 0 m/s. Let's call the final velocity of the blue ball v. The conservation of momentum equation is:

m_green x v_green + m_blue x v_blue = (m_green + m_blue)v

Substituting the values, we get:

10 kg x 10 m/s + 10 kg x 0 m/s = 20 kg x v

Simplifying, we get:

v = 5 m/s

b. When the green ball continues moving after the collision at 4 m/s in the same direction, its final velocity is 4 m/s. Let's call the final velocity of the blue ball v.

The conservation of momentum equation is the same as before:

m_green x v_green + m_blue x v_blue = (m_green + m_blue)v

Substituting the values, we get:

10 kg x 10 m/s + 10 kg x 0 m/s = 10 kg x 4 m/s + 10 kg x v

Simplifying, we get:

v = 6 m/s

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Answer:

An atom with an "unstable" nucleus is likely to split into two different atoms (elements) with emission of gamma, alpha, etc. which is radioactive radiation.

ChemBank matches small molecules to various biological targets and ChemBank uses known chemical compounds in new therapeutic applications are correct statements.

What is ChemBank?

ChemBank performs pure research and ChemBank applies its research to therapeutic goals could both be considered correct depending on the interpretation. ChemBank does perform pure research in the sense that it conducts basic scientific investigations to understand the properties and behavior of small molecules and their interactions with biological targets. However, ChemBank also applies its research to therapeutic goals by using this knowledge to develop new drugs and drug candidates.

ChemBank does not plan to sell the results of its research to various companies, so the statement "ChemBank plans to sell the results of its research to various companies" is incorrect.

ChemBank is not an open-source application, so the statement "ChemBank is an open-source application" is also incorrect.

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Complete question is: ChemBank matches small molecules to various biological targets and ChemBank uses known chemical compounds in new therapeutic applications are correct statements.

The rate of heat flow through the window is approximately 84.38 W.

The rate of heat flow through the window can be calculated using the formula:

Q = (kA (T1 - T2))/d

Where

We first need to convert the temperatures to Kelvin, since temperature differences must be in Kelvin in this formula:

T1 = 15.0°C + 273.15 = 288.15 K

T2 = 14.0°C + 273.15 = 287.15 K

The thermal conductivity of glass can vary depending on the type of glass, but a typical value is around k = 0.9 W/(m·K) for plate glass.

Substituting the given values into the formula, we get:

Q = (0.9 W/(m·K) x 2.0 m x 1.5 m x (288.15 K - 287.15 K))/0.0032 m

Simplifying this expression, we get:

Q ≈ 84.38 W

Therefore, the rate of heat flow through the window is approximately 84.38 W.

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Frequency=  30 Hz, Period= 0.0333 s, Wave Number=15.708 rad/m, Wave Function= y(x, t) = 0.05 sin(15.708x - 94.248t), Transverse displacement= -0.013 m, Time= 0.297 s.

(a) To find the frequency (f), we can use the equation: wave speed = frequency x wavelength. Rearranging this equation, we get:

frequency = wave speed / wavelength

Substituting the given values, we get:

frequency = 12 m/s / 0.4 m = 30 Hz

Therefore, the frequency of the wave is 30 Hz.

To find the period (T), we can use the equation:

period = 1 / frequency

Substituting the frequency value we just calculated, we get:

period = 1 / 30 Hz = 0.0333... s (rounded to four decimal places)

Therefore, the period of the wave is approximately 0.0333 s.

To find the wave number (k), we can use the equation:

wave number = 2π / wavelength

Substituting the given values, we get:

wave number = 2π / 0.4 m = 15.708 rad/m (rounded to three decimal places)

Therefore, the wave number of the wave is approximately 15.708 rad/m.

(b) The wave function for a transverse wave on a string is given by:

y(x, t) = A sin(kx - ωt + φ)

where A is the amplitude, k is the wave number, x is the position of the point on the string, t is the time, ω is the angular frequency, and φ is the phase constant.

We already know the values of A, k, and ω from the previous calculations. To find φ, we can use the given initial condition: "at t = 0 end of the string has zero displacement and is moving upward". This means that y(0,0) = 0 and ∂y/∂t(0,0) > 0. Substituting these conditions into the wave function, we get:

0 = A sin(0 + φ)

∂y/∂t = -Aω cos(0 + φ)

Since sin(0 + φ) = sin(φ) = 0 (because sin(0) = 0), we get:

φ = nπ, where n is an integer

Since cos(0 + φ) = cos(φ) = 1 (because cos(0) = 1) and ∂y/∂t(0,0) > 0, we get:

n = 0 or 2

Therefore, the possible values of φ are 0 or 2π.

Substituting the values of A, k, ω, and φ, we get:

y(x, t) = 0.05 sin(15.708x - 94.248t)

Therefore, the wave function describing the wave is:

y(x, t) = 0.05 sin(15.708x - 94.248t)

(c) To find the transverse displacement of a wave at x = 0.25 m and t = 0.15 s, we can use the wave function we just found:

y(0.25, 0.15) = 0.05 sin(15.708(0.25) - 94.248(0.15))

y(0.25, 0.15) ≈ -0.013 m (rounded to three decimal places)

Therefore, the transverse displacement of the wave at x = 0.25 m and t = 0.15 s is approximately -0.013 m.

(d) To find how much time must elapse from the instant in part (c) until the point at x = 0.25 m has zero displacement,

From part (c), we know that the transverse displacement of the wave at x = 0.25 m and t = 0.15 s is approximately -0.013 m. We need to find the time it takes for this point to return to zero displacement.

We can use the wave function we found in part (b) and set y(0.25, t) = 0:

0 = 0.05 sin(15.708(0.25) - 94.248t)

Since sin(θ) = 0 when θ = nπ (where n is an integer), we get:

15.708(0.25) - 94.248t = nπ

Solving for t, we get:

t = (15.708(0.25) - nπ) / 94.248

To find the smallest positive value of t that satisfies this equation, we need to use the smallest positive value of n that makes the right-hand side of the equation positive (because we want to find the time it takes for the point at x = 0.25 m to return to zero displacement, which happens after the point has completed a full cycle). We can see from the equation that n must be an even integer to make the right-hand side positive. The smallest even integer greater than zero is 2. Substituting n = 2, we get:

t = (15.708(0.25) - 2π) / 94.248

t ≈ 0.297 s (rounded to three decimal places)

Therefore, the time it takes for the point at x = 0.25 m to return to zero displacement is approximately 0.297 s.

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Answer:

The answer is 8%

Explanation:

We know that the efficiency of the machine is given by,

E=(M.A)*100

=([tex]\frac{20}{50}[/tex])*[tex]\frac{1}{5}[/tex]*100

=8%

Answer:

angle between A and B is approximately 76.8°

Explanation:

Using the cosine law, we can find the magnitude of the resultant vector R:

R^2 = A^2 + B^2 - 2ABcosθ

where θ is the angle between A and B, which can be found using the sine law:

sinθ/8m = sin60°/18m

θ ≈ 43.2°

Substituting the given values into the cosine law:

R^2 = (18m)^2 + (8m)^2 - 2(18m)(8m)cos(43.2°)

R ≈ 19.4m

The angle between R and A can be found using trigonometry:

tanθ = 8m/18m

θ ≈ 24.4°

Therefore, the angle between R and A is approximately 24.4°, and the angles between A and B and between B and R can be found using the fact that they form a triangle:

180° - 60° - 43.2° = 76.8°

Therefore, the angle between A and B is approximately 76.8°, and the angle between B and R is approximately 60° - 76.8° = -16.8° (because B is above the horizontal).

Ionic bonds bond ions together through their electric attraction to each other due to their opposite electrical charges.

In an ionic bond, one ion (typically a metal) loses one or more electrons and becomes a positively charged cation, while another ion (typically a nonmetal) gains one or more electrons and becomes a negatively charged anion. The opposite charges of the ions then attract each other, creating an ionic bond between them.

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Answer:

the answer is (d) the force which the ball exerts on the foot will be 40 N of reaction force.

Explanation:

According to Newton's third law of motion, for every action, there is an equal and opposite reaction. Therefore, the force exerted by the ball on the foot will be equal and opposite to the action force exerted by the foot on the ball.

Explanation:

It ignores some basic laws of physics:

  You cannot get more work out of a machine than goes in

    You cannot ignore friction

The resultant  wave is the combination of the two waves as we see in option A

A resultant wave is a wave that is formed when two or more waves interact with each other. When waves meet, they can interfere constructively, destructively, or somewhere in between, depending on their amplitude, phase, frequency, and direction. The resulting wave that emerges from this interaction is called the resultant wave.

The nature of the resultant wave depends on the type of interference that occurs between the waves. If the waves are in phase and have the same amplitude, they will interfere constructively, resulting in a wave with a larger amplitude.

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Answer:

When a social position is accompanied by accepted patterns of behavior, it becomes a role. A role is a set of expectations and behaviors that are associated with a particular social position. For example, a doctor's role includes expectations such as providing medical care to patients, making diagnoses, and prescribing treatments. Similarly, a teacher's role includes expectations such as instructing students, grading assignments, and providing feedback on student progress. Roles are important in society because they help to create order and stability, and they allow individuals to understand their place in society and how they are expected to behave.

Answer:

Each connection requires 50 centimeters of wire, which is equal to 0.5 meters of wire. Therefore, for eight connections, the electrician would need:

8 * 0.5 = 4 meters of wire

Therefore, the correct answer is option D, 4 m.

:

In a tractor pull, a tractor put 250,000 J of work into pulling a large mass. The tractor pulls the mass using 98,000N of force. The tractor pulled the mass to a distance of 2.55 meters

We may use the work done formula to solve this problem:

Work = Force  x Distance x Cosine (angle between force and displacement)

Yet, because the force and displacement are applied in the same direction, the angle between them is zero, and the cosine of zero is one. As a result, we may reduce the formula to:

Work = Force x Distance

Because we know the work done is 250,000 J and the force exerted is 98,000 N, we can rewrite the formula to solve for distance:

Distance = Work / Force

Distance = 250,000 J / 98,000 N

Distance = 2.55 meters

As a result, The tractor pulled the mass to a distance of 2.55 meters

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The man who walks at 3.56 m/s and accelerates at 2.50 m/s2 for 9.28 s would walk a distance of  135.245 meters.

We can use the kinematic equation:

distance = initial velocity x time + (1/2) x acceleration x time^2

To use this equation, we need to find the initial velocity of the man before he started accelerating. We can do this using the formula:

final velocity = initial velocity + acceleration x time

At the start, the man's velocity was 3.56 m/s, and he accelerates at 2.50 m/s^2 for 9.28 s. Therefore, his final velocity can be calculated as:

final velocity = 3.56 + 2.50 x 9.28

final velocity = 26.08 m/s

Now we can use the distance formula:

distance = initial velocity x time + (1/2) x acceleration x time^2

with initial velocity being 3.56 m/s, time being 9.28 s, acceleration being 2.50 m/s^2, and final velocity being 26.08 m/s:

distance = 3.56 x 9.28 + (1/2) x 2.50 x (9.28)^2

distance = 32.968 + 102.277

distance = 135.245 m

Therefore, the man traveled a distance of approximately 135.245 meters.

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Answer:

Options B

Explanation:

The appropriate quantitative research method for understanding political views held by the young population of a specific area is written surveys (option b). Surveys allow for the collection of data from a large number of participants, and specific questions can be asked to gather data on political views.

Participant observation (option a) involves direct observation of individuals in a natural setting, which may not be practical for studying political views.

Secondary data analysis (option c) involves analyzing data that has already been collected, and may not be specific to the young population or the area of interest.

Laboratory experiments (option d) are typically used to study cause-and-effect relationships between variables, which may not be applicable to studying political views.

Therefore, the best option for understanding the political views held by the young population of a specific area is written surveys.

To understand the political views of the young population of a specific area, a researcher can use written surveys, participant observation, and secondary data analysis as quantitative research methods.

If a researcher is trying to understand the political views held by the young population of a specific area, they should use written surveys, participant observation, and secondary data analysis as quantitative research methods.

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the magnitude of the electric field in the region between the plates is 1.44 × [tex]10^6[/tex]V/m.

The electric field between the plates of the CRT can be calculated using the formula:

E = V/d

where E is the electric field, V is the potential difference across the plates, and d is the distance between the plates.

Substituting the given values, we get:

E = 24.5 kV / 0.017 m

Converting kV to V and simplifying, we get:

E = 24.5 × [tex]10^3[/tex]V / 0.017 m

E = 1.44 × [tex]10^6[/tex] V/m

An electric field is a force field created by a charged object or collection of charged objects that exerts a force on other charged objects within its vicinity. The electric field is a vector quantity and is measured in units of volts per meter (V/m).

The electric field at a point in space is defined as the force per unit charge acting on a positive test charge placed at that point. The direction of the electric field is given by the direction of the force that would be experienced by a positive test charge placed at that point.

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Note that the wave function of (Px)^2 is given by: (Px)^2 Psi(x) = (h^2/4π^2) [(3α^2 x^2 - α) (α/π)^(1/4) e^(-αx^2/2)]

To find the wave function of (Px)^2, we need to use the momentum operator, which is represented by Px = -i(h/2π) d/dx.

First, let's find the wave function of Px, which is given by:

Px Psi(x) = -i(h/2π) d/dx [Psi(x)]

= -i(h/2π) [-αx Psi(x) + (α^2 x) Psi(x)]

Now, we can find the wave function of (Px)^2 by squaring the wave function of Px:

(Px)^2 Psi(x) = (-i(h/2π) d/dx) (-i(h/2π) d/dx) Psi(x)

= (h^2/4π^2) [α^2 x^2 Psi(x) - 2α x d/dx(Psi(x)) + (d^2/dx^2)(Psi(x))]

Substituting Psi(x) = (α/π)^(1/4) e^(-αx^2/2) into the above expression, we get:

(Px)^2 Psi(x) = (h^2/4π^2) [(3α^2 x^2 - α) (α/π)^(1/4) e^(-αx^2/2)]

Therefore, the wave function of (Px)^2 is given by:

(Px)^2 Psi(x) = (h^2/4π^2) [(3α^2 x^2 - α) (α/π)^(1/4) e^(-αx^2/2)]

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Therefore, the answer is (a) 1292 cm is stick has a shadow when held vertical.

Additionally, since light moves in a straight path from its source to an object, the shadow of the object moves with the light source.

Let's use h centimetres to represent the tree's height. We have the following percentage in the problem:

height of tree/length of its shadow = height of meter stick/length of its shadow

or

h / 4200 = 100 / 325

We can solve this proportion for h:

h = 4200 * 100 / 325 = 1292.31 cm

Rounding to the nearest centimeter, we get:

h ≈ 1292 cm

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the pressure of the water after the contraction is -50000 Pa (or 50 kPa below atmospheric pressure), and the velocity of the water after the contraction is 15.0 m/s.

The continuity equation states that the product of the cross-sectional area and the velocity of an incompressible fluid is constant along a pipe, so we can use it to relate the pressure and velocity before and after the contraction:

A₁v₁ = A₂v₂

where A₁ and v₁ are the area and velocity of the pipe before the contraction, and A₂ and v₂ are the area and velocity of the pipe after the contraction.

We can also use the Bernoulli equation, which relates the pressure and velocity of a fluid along a streamline:

P₁ + 1/2 ρv₁² = P₂ + 1/2 ρv₂²

where P₁ and v₁ are the pressure and velocity of the fluid before the contraction, and P₂ and v₂ are the pressure and velocity of the fluid after the contraction, and ρ is the density of the fluid, which we assume to be constant.

Solving for the pressure and velocity after the contraction, we can use the continuity equation to express v₁ in terms of v₂ and substitute it into the Bernoulli equation:

A₁v₁ = A₂v₂

v₁ = (A₂/A₁) v₂

P₁ + 1/2 ρ((A₂/A₁) v₂)² = P₂ + 1/2 ρv₂²

Simplifying and solving for P₂, we get:

P₂ = P₁ + 1/2 ρ(v₁² - v₂²)

Substituting the given values, we get:

A₂ = (1/3) A₁

v₁ = 5.0 m/s

P₁ = 450000 Pa

ρ = 1000 kg/m³

Using the continuity equation, we can find the value of v₂:

A₁v₁ = A₂v₂

v₂ = (A₁/A₂) v₁

v₂ = 3 × 5.0 m/s

v₂ = 15.0 m/s

Substituting this value into the Bernoulli equation, we can find the pressure P₂:

P₂ = P₁ + 1/2 ρ(v₁² - v₂²)

P₂ = 450000 Pa + 1/2 × 1000 kg/m³ × (5.0 m/s)² - (15.0 m/s)²

P₂ = 450000 Pa - 500000 Pa

P₂ = -50000 Pa

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Answer:

line graph. A line graph is the best way to show changes in data over time. The geographer can plot the economic growth of one country as a line going up over the 10 years, and the economic decline of the other country as a line going down slightly over the same period. This will allow for a clear visual comparison of the changes in the economies of the two countries over time.

Answer:

To solve this problem, we need to use the following formula:

Q = m_tea * c_tea * (T_f - T_i) + m_ice * L_f + m_ice * c_ice * (T_f - 0)

where Q is the amount of heat transferred, m_tea is the mass of the tea, c_tea is the specific heat capacity of the tea, T_i is the initial temperature of the tea, T_f is the final temperature of the tea and ice mixture, m_ice is the mass of the ice, L_f is the latent heat of fusion of ice (334 J/g), and c_ice is the specific heat capacity of ice (2.108 J/g·°C).

First, we need to calculate the initial temperature of the tea. Since it has reached an equilibrium temperature of 33.3°C in sunlight, we can assume that its initial temperature was also 33.3°C.

So, the equation becomes:

Q = (187 g) * (4186 J/kg·°C) * (31.8°C - 33.3°C) + (133 g) * (334 J/g) + (m_ice) * (2.108 J/g·°C) * (31.8°C - 0°C)

Simplifying this equation, we get:

Q = -121732.8 J + 44422 J + 67.032 m_ice

Setting Q to zero, since we want to find the mass of the remaining ice when the temperature is 31.8°C, we get:

67.032 m_ice = 121732.8 J - 44422 J

m_ice = 114.9 g

Therefore, the mass of the remaining ice in the jar when the temperature is 31.8°C is 114.9 g (to 2 significant digits).

We can use the kinetic equation that combines velocity, acceleration, and time to calculate the number of months until the bank account is empty:

[tex]v = v_0 + at[/tex]

Since initially there is no net change in the account balance, the initial velocity [tex](v_0)[/tex]in this case is 0. 22.5 * $102 per month expressed as Acceleration (a). The moment (t) at which the account balance reaches zero must be determined.

We can arrange the equation to solve for time as follows:

[tex]0 = 0 + (22.5 * 10^2) * t[/tex]

When we simplify the equation, we get:

2250t = 0

After 0 months the account balance will be zero as the result of the calculation will be 0. This shows that the bank account is currently empty or will be empty soon.

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Explanation:

See image for definitions....look at the units and fill the blanks appropriatly

Answer:

The acceleration of an air cart, which is an object moving on a cushion of air, would not change when adding mass to it because the force of air resistance acting on the cart is negligible compared to the force applied by the air source that propels it. Therefore, the total force acting on the cart remains almost constant, regardless of the cart's mass, and according to Newton's second law of motion, the cart's acceleration would remain the same. This assumes that the air source provides a constant force and that the added mass does not significantly affect the friction between the cart and the surface on which it is moving.

The equation of motion of a one dimensional standing wave can be derived from first principles using the wave equation.

The wave equation states that the propagation speed of a wave, c, is equal to the square root of the ratio of the wave's tension (T) to its linear mass density (μ). In other words,

[tex]c = \sqrt{ \frac{T}{\mu}[/tex]

For a one dimensional standing wave, the equation of motion can be derived by taking the second derivative of the wave equation with respect to time. This is the equation of motion that results:

[tex]F = \mu (\frac{d2y}{dt2})[/tex]

where F is the total force applied to the wave, and [tex]\frac{dy}{dt}[/tex] is the wave velocity. The equation of motion can be further simplified by substituting the wave equation for c, resulting in the following equation of motion for a one dimensional standing wave:

[tex]F = (\frac{T}{\mu }) (\frac{d2y}{dt2})[/tex]

This equation of motion describes how the total force applied to a one dimensional standing wave affects the wave's velocity.

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complete question:What is the equation of motion for a one-dimensional standing wave?

The buoyant force always pushes objects up toward the surface of the fluid because it is the upward force that acts on an object submerged in a fluid, such as water or air.

This upward force is known as the buoyant force and is equal to the weight of the fluid displaced by the object which means that the buoyant force is always pushing the object up toward the surface of the fluid. In general, the buoyant force is stronger than gravity when the object is less dense than the fluid and weaker when the object is more dense than the fluid. Thus, the force of gravity is always pulling objects down, but the buoyant force can be stronger or weaker than gravity depending on the object’s density and the density of the fluid. Hence, the buoyant force always pushes objects up toward the surface of the fluid, regardless of whether the fluid is water, air, or some other fluid.

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The simulation of sound waves bouncing off a flat surface is one model that most accurately depicts what happens when sound waves are reflected.

The term "echo" refers to a sound reflection that follows a direct sound in reaching the listener. The delay increases with the distance between the source and the listener travelled by the reflecting surface.

Longitudinal waves are those produced by sound. Compressions and rarefactions occur during the propagation of longitudinal waves through any given medium. When particles are compressed, high pressure zones are created as a result of their near proximity.

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