The second law of thermodynamics states that
a change in a system's energy is equal to the energy
transferred to the system.
energy cannot be created or destroyed.
energy can flow from a colder object to a warmer object
only if something does work.
the only way to reduce an object's temperature is to
increase the entropy of the environment.
Answers
Answer: energy can flow from a colder object to a warmer object
only if something does work.
Explanation: Consider the flow of water from a higher level to a lower level. There is no need to use energy to make this process occur. This type of process which does not need the application of energy to take place is said to be spontaneous. But to make water go up to the water tank, a pump must be used to make the process take place. This type of process which needs the use of energy to make it happen is said to be nonspontaneous.
but why not the only way to reduce an object's temperature is to
increase the entropy of the environment.?
coz the motion of particles decreases and their velocity decreases so they have less entropy at a lower temperature.
hope it helped:)
Related Questions
Why might earthquakes be much more intense closer to the initial disturbance than they are further away
Answers
Earthquakes are typically more intense closer to the initial disturbance because the seismic waves generated by the earthquake lose energy as they travel through the Earth's crust. The energy of the seismic waves is dissipated as they encounter different layers of rock and other materials, causing the waves to become weaker and less intense.
Closer to the initial disturbance, the seismic waves encounter less material to pass through, and therefore experience less energy loss. As a result, the waves are more intense and can cause more damage to structures and the surrounding environment.
In addition to this, the type of rock and soil that the seismic waves pass through can also affect their intensity. Softer materials like sand and clay amplify the seismic waves, which can cause more damage in the nearby areas.
Therefore, the distance from the initial disturbance and the geological features of the region can both affect the intensity of an earthquake. Typically, the closer an area is to the epicenter of an earthquake, the more intense the shaking will be, and the further away an area is, the weaker the shaking will be.
_______, ________, and ________ are renewable resources.
biomass energy, hydropower, and coal energy
hydropower, coal energy, and wind energy
biomass energy, hydropower, and wind energy
biomass energy, coal energy, and wind energy
✎help its an exam✎ ☕︎if any links I WILL REPORT☕︎
Answers
Answer:
biomass energy, hydropower and wind energy
Jeremiah is conducting an investigation about the water cycle. He is given the following materials:
a lamp
a glass jar that contains water
plastic wrap
Describe how Jeremiah can arrange these materials to create a model that shows the processes by which water is cycled from a lake into the atmosphere and back to the lake. Be sure to identify what each material represents in the model.
Answers
Answer:
The water cycle outlines the continuous water movement in liquid, solid and gaseous state between locations on the Earth's surface.
The glass jar represents the lake while the atmosphere is represented by the space above the water, and the sky is represented by the (clear) plastic wrap
Arrangement description and Processes;
The processes of the water cycle includes;
Evaporation;
Condensation
Precipitation
Sublimation
Runoff
Infiltration
The arrangement of the materials is as follows;
Place the glass jar (the lake) containing water and the lamp (the Sun) side by side, such that the lamp light shines on the water surface
Cover the glass jar by wrapping the plastic wrap (the sky) around it to prevent the escape of water vapor when the water is hot.
Switch on the lamp so that it heats the water by radiation heat transfer
Observed processes;
The processes demonstrated by the above experiment includes;
1) Evaporation: As the water in the glass jar becomes warmer, the level of the water in the jar can be observed to decrease slightly due to evaporation
2) Condensation: Fog formation, Clouds
When hotter, the water surface as seen through the clear plastic wrap becomes less clearer due to evaporation, and condensation of the vapor while floating above the water surface, similar to the clouds seen in the sky.
3. Precipitation: Rain;
The clear plastic wrap covering the top of the glass jar, prevents the movement of the vapor further away, such that the tiny condensed vapor gather together, to form big droplets under the plastic wrap that falls back into the jar, which is similar to the process of rainfall
The above processes are repeated as more water evaporates from the jar condenses on the plastic wrap and falls back into the jar, showing the process by which water is recycled from the lake into the atmosphere and back to the lake.
Explanation:
What type of circuit is shown
Answers
=When three resistors are connected in parallel, they form a parallel circuit. In a parallel circuit, each resistor is connected across the same two points, with the current split between the resistors.
In this configuration, the voltage across each resistor is the same, but the current through each resistor can be different. The total resistance of the circuit is calculated using the equation:
1/R_total = 1/R1 + 1/R2 + 1/R3
where R1, R2, and R3 are the resistance values of the individual resistors.
The total current in the circuit is equal to the sum of the currents through each resistor:
I_total = I1 + I2 + I3
where I1, I2, and I3 are the currents through each resistor.
The total power dissipated in the circuit can be calculated using the equation:
P_total = V² / R_total
where V is the voltage across the resistors.
In summary, when three resistors are connected in parallel, they form a parallel circuit, with each resistor connected across the same two points, and the current split between them. The total resistance, current, and power dissipated in the circuit can be calculated using the equations provided.
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A boy of mass 60 kg and a girl of mass 40 kg are together and at rest on a frozen pond and push each other apart. The girl moves in a negative direction with a speed of 3 m/s. What must be the final momentum of the boy?
A. 100 kgm/s
B. 120 kgm/s
C. -120 kgm/s
D. 40 kgm/s
Answers
Answer:
B. 120 kgm/s
Explanation:
The initial momentum of the system is zero since the boy and the girl are at rest. When they push each other apart, the total momentum of the system remains conserved. Since the girl moves in a negative direction, the boy must move in the positive direction with the same momentum to keep the total momentum of the system zero.
Let's assume the final momentum of the boy is p. According to the law of conservation of momentum,
(initial momentum) = (final momentum)
0 = p + (-40 kg)(-3 m/s)
0 = p + 120 kg m/s
p = -120 kg m/s
Therefore, the final momentum of the boy must be 120 kg m/s in the positive direction, which is answer choice B.
Ans
According to the law of conservation of momentum, the total momentum of the system before and after the interaction must be equal. Initially, the momentum of the system is zero since the boy and the girl are at rest. When they push each other, the girl moves in the negative direction with a speed of 3 m/s. Let's assume that the boy moves in the positive direction with a speed of v m/s.
The total initial momentum of the system is:
P_initial = m_boy * 0 + m_girl * 0 = 0
The total final momentum of the system must also be zero since there are no external forces acting on the system. Therefore:
P_final = m_boy * v + m_girl * (-3) = 0
where m_boy = 60 kg, m_girl = 40 kg, and v is the final speed of the boy in m/s.
Solving for v, we get:
60v - 120 = 0
v = 2 m/s
Therefore, the total final momentum of the boy must be:
P_final = m_boy * v = 60 kg * 2 m/s = 120 kg m/s.
So, the total final momentum of the boy must be 120 kg m/s.
4.
The "force" that moves electric charge carriers through an electric circuit is
a superconductor
resistance
An
10
a
MacBook Air
s
8
current
voltage
DII
8
A
EMA
4
F11
F12
Answers
Answer: Voltage
Explanation: Not really sure what all that other stuff is after your question...
The "force" that moves electric charge carriers through an electric circuit is ________.
An electric charge carrier moving through a circuit is a charged particle (usually electrons). The force that pushes it is called an electromagnetic force, commonly known as EMF.
Between atoms, EMFs are what attract electrons from one atom to another to form bonds. Likewise, In a circuit, the EMF is the driving force, which is known as voltage.
Superconductivity refers to a state in which these charge carriers travel at a specific voltage with no resistance, meaning no energy is lost. However, this isn't an independent force, so it's incorrect.
Resistance affects the circuit by slightly dampening the flow of charge carriers. Resistance commonly comes in the form of temperature or simply a characteristic of the material through which the circuit flows, so this is incorrect.
Current merely refers to the flow of charge carriers through a circuit in a given time window.
(Think of a circuit as a water pipe. Current is like the speed of a specific amount of water and Voltage (or EMF) is the pressure in the pipe. The higher the pressure, the faster the water flows. Resistance is anything in the pipe that impedes the water flow)
A blue train of mass 50 kg moves at 4 m/s toward a green train of 30 kg initially at rest. What is the initial momentum of the blue train?
A. 20 kgm/s
B. 200 kgm/s
C. 50 kgm/s
D. 0 kgm/s
Answers
Answer:
B. 200 kgm/s
Explanation:
The initial momentum of the blue train can be calculated using the formula:
p = mv
where p is the momentum, m is the mass, and v is the velocity.
The mass of the blue train is 50 kg and its velocity is 4 m/s. Therefore, the initial momentum of the blue train is:
p = 50 kg x 4 m/s = 200 kgm/s
Therefore, the initial momentum of the blue train is 200 kgm/s, which is option B.
what are the two major types of mechanical energy and how do you calculate each equations with variables identified?
Answers
The equation to calculate both of them are:
KE = 1/2 * m * v^2
PE = m * g * h
What is Kinetic energy?Kinetic energy is described as the energy an object possesses due to its motion. The equation to calculate kinetic energy is:
KE = 1/2 * m * v^2
Where:
KE = Kinetic energy
m = Mass of the object
v = Velocity of the object
Potential energy is described as the energy an object possesses due to its position or configuration.
. The equation to calculate gravitational potential energy is:
PE = m * g * h
Where:
PE = Gravitational potential energy
m = Mass of the object
g = Acceleration due to gravity (9.81 m/s^2 on Earth)
h = Height or elevation of the object relative to a reference point
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A tourist, who weighs 705 N, is walking through the woods and crosses a small horizontal bridge. The bridge rests on two concrete supports, one at each end. He stops on the bridge. Assume that the board of the bridge has negligible weight. Where is he standing if the magnitude of the vertical force that a concrete support exerts on the bridge at the near end is 470 N?
а)one-fifth of the way along the bridge b)one-fourth of the way along the bridge c)one-third of the way along the bridge d)one-half of the way along the bridge f)one-sixth of the way along the bridge
Answers
The tourist is standing one-third of the way along the bridge (option c).
How to solveLet's denote the distance from the near end of the bridge to the point where the tourist is standing as x and the total length of the bridge as L.
According to the equilibrium condition, the sum of the forces exerted on the bridge is zero.
So, the vertical forces exerted by the two concrete supports should be equal to the weight of the tourist:
F_near + F_far = 705 N
Given that the magnitude of the vertical force exerted by the near end support is 470 N, we can calculate the force exerted by the far end support:
F_far = 705 N - 470 N = 235 N
Now, we can use the moment equilibrium condition, considering moments around the near end support:
Moment = Force × Distance
For the tourist:
Moment_tourist = 705 N × x
For the far end support:
Moment_far = 235 N × L
For equilibrium, the sum of the moments should be zero:
Moment_tourist - Moment_far = 0
Substituting the moments:
705 N × x - 235 N × L = 0
Now, we can solve for x/L, which represents the fraction of the way along the bridge where the tourist is standing:
x/L = (235 N × L) / 705 N
x/L = 235/705 = 47/141 ≈ 1/3
So, the tourist is standing one-third of the way along the bridge (option c).
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Use the heating curve (Figure 1) to answer the question.
Temperature (°C)
200
150
100
50
0
-50
-100
-150
200 400 600 800 1000 1200
Energy (J)
What is the boiling point of the substance represented?
0
-100 °C
150 °C
-50 °C
50 °C
Answers
Answer:
Melting Point = -50 °C
Boiling Point = 50 °C
Explanation:
A heating curve displays a substance in its 3 states.
On the graph, each region where the slope is positive represents the substance as a solid, liquid, or gas.
When the slope is 0, this is the temperature point at which the substance's state of matter has changed (i.e., melting or boiling/vaporization point) – also known as a phase transition. Essentially, the 0 slope regions are where the substance is changing from one state of matter to the next.
(When the substance is being heated, it's absorbing energy, but when it reaches a phase transition point, the substance begins to consume energy to change its matter state. That's why the temperature doesn't go up while the substance's internal Energy increases.)
In (Figure 1), where 'x' is Energy (J) and 'y' is Temperature (°C):
Region A (0 J ≤ x ≤ 200 J):
The slope is positive, so the substance is in a constant matter state. Because it's the first sloped region, the substance is in its solid state from -100 °C to -50 °C.
Region B (200 J ≤ x 600 J):
The slope is 0, so the substance has reached a phase transition point. Because the previous region was when the substance was solid, that means that the temperature throughout Region B is the melting point at -50 °C.
Region C (600 J ≤ x ≤ 800 J):
The slope is positive so the substance is in a constant matter state. We've already identified when the substance was solid and when it melted, so now the substance is in its liquid state from -50 °C to 50 °C.
Region D (800 J ≤ x ≤ 900 J):
The slope is 0, and since the previous region was when the substance was a liquid, it's now reached its boiling point at 50 °C.
Region E (900 J ≤ x ≤ 1000 J):
The slope is positive, and we've previously identified all of the transition points and matter states except for one, so the substance is now in its gaseous state after reaching 100°C.
(Once a substance reaches its gaseous state, the Temperature/Energy ratio is constant.)
[Rotational motion] Calculate the length L between the 40N weight and the pivot needed to balance the beam shown in Figure 10.9. (solution says it's 7 m but it's unclear how it was obtained)
Answers
Answer:
L = 7m
Explanation:
The beam is balanced (not moving), so the moments about the pivot have to sum to 0.
Let x = dist. from pivot to the 10N ↓ force
CCW rotation is +
CW rotation is -
(100 N)(3 m) - (10 N)(x) - (40 N)(L) = 0
300 N·m - (10 N)(x) - (40 N)(L) = 0 divide by 10 on both sides
30 - x - 4L = 0
x + 4L = 30
10N is the Weight of the beam, so it is at the midpoint of the beam.
x = 5 - 3 = 2 m substitute into the equation above:
2 + 4L = 30
4L = 30 - 2 = 28
L = 28/4 = 7 m
A mass of 10kg suspended on a steel rod of length 2m and radius 1mm what is the elongation of the rod beyond it's original length (Take E = 200*10^9 Newton per metre square
Answers
The elongation of the rod beyond its original length would be 2.5 mm.
Elongation calculationTo elongation of the rod can be deduced using the formula:
ΔL = FL / AE
where:
ΔL is the elongationF is the force appliedL is the original length of the rodA is the cross-sectional area of the rodE is Young's modulus of elasticity of the material.The cross-sectional area of the steel rod is given by:
A = π[tex]r^2[/tex]A = π[tex](0.001 m)^2[/tex] = 7.85 x [tex]10^{-7} m^2[/tex]The force applied to the rod:
F = mgF = 10 x 9.81 = 98.1 NThus:
ΔL = (98.1 x 2) / ((7.85 x [tex]10^{-7[/tex]) x (200 x [tex]10^9[/tex] ))
ΔL = 0.0025 m = 2.5 mm
In other words, the elongation of the steel rod beyond its original length is 2.5 mm.
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5. An elephant has weight of 48000N and exerts pressure of 60000 Pa on the ground. What is the area of the elephant's feet in contact with the ground?
a. 1.25 m^2
b. 0.8 m^2
c. 2.0 m^2
d. 8.0 m^2
Answers
Answer:
A 1.25 m²
Explanation:
What is amplitude and phase in electrical and electronics circuit?
Answers
In electrical and electronics circuits, amplitude is the maximum value of a signal. This is known as the strength or intensity of the signal. Phase, can be seen as the timing relationship between two signals or waveforms. It tell the time it takes betwen the peaks or zero crossings of two waveforms
What more should you know about phase in electrical and electronics circuits?In electrical and electronics circuits, phase tell us about the the relationship between currents in different parts of the circuit, For example in AC circuits with multiple components.
We the amplitude and phase of signals in electrical and electronics circuits is understood, it becomes easier to design and analyz circuits, and can even be used for troubleshooting and maintaining them.
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1.
Which of the following is not true concerning sound waves?
Sound requires a medium.
Sound waves are longitudinal waves.
MacBook Air
Sound requires a vibrating object.
Sound waves cause particles to vibrate perpendicular to
the direction of the wave.
Answers
Answer:
Sound waves cause particles to vibrate perpendicular to the direction of the wave.
If you have a potential energy of 57 J. Now double your height, what is your new potential energy?
Answers
The new potential energy you will have, given that your height is doubled is 114 J
How do i determine the new potential energy?The following data were obtained from the question:
Initial potential energy (PE₁) = 57 JInitial height (h₁) = HNew height (h₂) = double of initial height = 2HNew potential energy (PE₂) =?The new potential energy can be obtained as illustrated below:
PE₁ / h₁ = PE₂ / h₂
57 / H = PE₂ / 2H
Cross multiply
57 × 2H = PE₂ × H
Divide both sides by H
PE₂ = (57 × 2H) / H
PE₂ = 57 × 2
PE₂ = 114 J
Thus, from the above calculation, we can conclude that the new potential energy is 114 J
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Sean throws a baseball at an angle of 25 relative to the ground at a speed of 23m/s. What is the maximum height the ball will achieve? How long will it be in the air? How far away does Kelly need to be to catch the ball?
Answers
Answer:
To solve this problem, we can use the equations of motion for projectile motion:
- Vertical displacement: Δy = v₀sinθt - 1/2gt²
- Vertical velocity: v = v₀sinθ - gt
- Time of flight: T = 2v₀sinθ/g
- Horizontal displacement: Δx = v₀cosθt
where v₀ is the initial speed, θ is the angle of projection, g is the acceleration due to gravity (9.81 m/s²), t is the time of flight, and Δy and Δx are the vertical and horizontal displacements, respectively.
First, we can find the maximum height by using the equation for vertical displacement:
Δy = v₀sinθt - 1/2gt²
At the maximum height, the vertical velocity is zero, so we can find the time of flight by setting the vertical velocity equation to zero:
v = v₀sinθ - gt = 0
Solving for t, we get:
t = v₀sinθ/g
Substituting this into the equation for vertical displacement, we get:
Δy = v₀sinθ(v₀sinθ/g) - 1/2g(v₀sinθ/g)²
Simplifying, we get:
Δy = (v₀²sin²θ)/(2g)
Substituting the given values, we get:
Δy = (23²sin²25)/(2*9.81) ≈ 29.4 m
So the maximum height is approximately 29.4 meters.
Next, we can find the time of flight using the equation for time of flight:
T = 2v₀sinθ/g
Substituting the given values, we get:
T = 2*23*sin25/9.81 ≈ 3.5 s
So the time of flight is approximately 3.5 seconds.
Finally, we can find the horizontal displacement using the equation for horizontal displacement:
Δx = v₀cosθt
Substituting the given values, we get:
Δx = 23*cos25*3.5 ≈ 64.3 m
So Kelly needs to be approximately 64.3 meters away to catch the ball.
What particle carries electric charge between your body and carpet when you experience static electricity?
Answers
Answer:
an electron.
Explanation:
When you walk on a carpet, some of the electrons from the atoms in the carpet are transferred to your body, giving you a negative charge. The electrons are then transferred back to the carpet when you touch a conductor, such as a doorknob, which can give you a shock due to the discharge of the static electricity.
What is the magnitude of the force in coulomb's law when one of the charge is double
Answers
Answer: Doubled
Explanation:
what is the net charge when you rub a plastic ruler with fur
Answers
The net charge when you rub a plastic ruler with fur would be infinitesimal or zero
How to detect the net chargeThe effect of friction between a plastic ruler and fur is evident when electrons are transferred from the hairy surface to the ruler's plane, ending with the ruler possessing a negative charge while the fur taking on a positive one.
As a result, the whole system presents with a net charge that is negative it converges due to the excess electrons now found on the ruler. However, occasionally, the magnitude of this charge is very small, consequently making it difficult to probe without reliable technology or instruments.
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A 0.530-kg cart moving at 0.572 m/s to the right collides elastically with a 0.25-kg cart initially at rest. The 0.25-kg cart then moves off rapidly and compresses a spring before the 0.530-kg cart can catch it again.
Answers
To solve this problem, we can use the conservation of momentum and the conservation of kinetic energy.First, let's find the velocity of the 0.530-kg cart after the collision. We can use the conservation of momentum:m1v1 + m2v2 = m1v1' + m2v2'where m1 and v1 are the mass and velocity of the 0.530-kg cart before the collision, m2 and v2 are the mass and velocity of the 0.25-kg cart before the collision, and v1' and v2' are the velocities of the carts after the collision.Plugging in the numbers, we get:(0.530 kg)(0.572 m/s) + (0.25 kg)(0 m/s) = (0.530 kg)v1' + (0.25 kg)v2'Solving for v1', we get:v1' = [(0.530 kg)(0.572 m/s) + (0.25 kg)(0 m/s)] / (0.530 kg + 0.25 kg) = 0.378 m/s to the rightSo the 0.530-kg cart moves off to the right at 0.378 m/s after the collision.Next, let's find the maximum compression of the spring. We can use the conservation of kinetic energy:(1/2)m2v2^2 = (1/2)kx^2where k is the spring constant and x is the maximum compression of the spring.We know the mass and velocity of the 0.25-kg cart before the collision (v2 = 0 m/s), so we can solve for k:k = 2(1/2)m2v2^2 / x^2 = m2v2^2 / x^2Plugging in the numbers, we get:k = (0.25 kg)(0 m/s)^2 / x^2 = 0This means that the spring constant is 0, which is not physically possible. Therefore, there must be an error in the problem statement or some missing information that would allow us to calculate the maximum compression of the spring.
A flashlight bulb is connected to a dry cell of voltage 5.25 V. It draws 15 mA (1,000 mA = 1 A). Its resistance is
2.5 E2 ohms
3.0 E2 ohms
3.5 E2 ohms
4.0 E2 ohms
Answers
____________________________________
C) 3.5 ΩOhm's Law: R = V / I × 10= 5.25 ÷ 15mAh × 10= 3.5 Ω____________________________________
Why did Izzy fall when playing tug of war? Responses he tripped he tripped balanced forces balanced forces he was pushed he was pushed unbalanced forces
Answers
Answer:
he tripped ballanced forces ballanced forces
What is the S-P difference (sec)?
What is the amplitude (mm)?
What is the distance (km)?
What is the magnitude (M)?
Answers
Amplitude is the maximum vertical displacement of the seismic waves on the Seismogram. As evident from the graph, it is 60 mm.
What is the Time?1. Time at which P waves arrive- 0 sec
Time at which S waves arrive- 18 sec
S-P interval= Time at which S wave arrive- Time at which P wave arrive
S-P interval= 18-0= 18 sec
2. Amplitude is the maximum vertical displacement of the seismic waves on the Seismogram. As evident from the graph, it is 60 mm.
3. The distance is around 150 km and is evident on the Distance/S-P bar chart.
4. The magnitude is about 4 and can be found by joining S-P interval (18 sec) with the Amplitude i.e., 6 mm. The point of intersection of the line to the magnitude line gives the magnitude, i.e., 4.
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HELP!!! You have two substances, both of which have the same boiling point (or attraction between their molecules).
The first substance is made from molecules that are small (just a few atoms bonded together), and the second substance is made from mol that are larger (many atoms bonded together).
How can it be possible for two such different molecules to yield substances with the same boiling point? Describe the kinds of intermolecu attractions that must be involved and any other properties of the molecules that could cause this result.
Answers
Despite having different molecular sizes, two substances can have the same boiling point due to the presence of intermolecular attractions that compensate for the difference in molecular weight.
What is the explanation for the above response?Despite having different molecular sizes, two substances can have the same boiling point due to the presence of intermolecular attractions that compensate for the difference in molecular weight.
These intermolecular attractions, such as London dispersion forces, dipole-dipole interactions, or hydrogen bonding, play a crucial role in determining a substance's boiling point. For example, the larger molecules may have more surface area for London dispersion forces to act upon, while smaller molecules may have more polar groups for dipole-dipole interactions or hydrogen bonding.
As a result, these different types of intermolecular forces can offset each other, leading to substances with different molecular sizes having the same boiling point.
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What is the definition of physical activity?
A.
a movement that stimulates your respiratory system
B.
a movement that causes perspiration
C.
a movement that results in the body’s use of energy
D.
a movement that requires little effort
Answers
Answer: The answer is C
Explanation: because I got it correct
C. A movement that results in the body's use of energy.
WHO has defined physical activity as any bodily movement that requires expenditure of energy.
Physical activity includes both exercise as well as integrated activities of one's daily routine.
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convert 750W into kilowatts
Answers
Ans. 0.75
To convert watts into kilowatts we must divide it by 1000
so dividing 750W by 1000
we get,
750/1000 = 0.75
hence 750W in kilowatts equals to 0.75
Researchers want to assess your intelligence. To do so, they have you
complete a short survey on which you indicate your favorite color. They ask
you to complete this survey multiple times, and you always answer the same
color. Unfortunately, one's favorite color has nothing to do with one's
intelligence. This research survey is best defined as:
Answers
This research survey is an example of a flawed or invalid measure of intelligence.
The research survey that is shown in this question can be defined as a poor measurement tool for assessing intelligence. One can easily identify that the researchers are measuring intelligence by asking about the favorite color of the personnel, which has nothing to do with the intelligence of the person. This survey lack validity which is essential to measure the intelligence of any personnel through a survey.
The survey also lacks reliability as it can't provide consistent results. If the intelligence of any personnel is somehow related to the intelligence of the person, answering the survey multiple times must give the same answer. This doesn't provide consistent result and lack reliability and realism.
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Two whistles emit sounds of wavelength 3.2 m and 2.9 m which produce a beat frequency of about? a) 2 hertz b) 3 hertz c) 4 hertz d) 7 hertz e) 11 hertz
Answers
Two whistles emitting sound of wavelength 3.2 m and 2.9 m would produce a beat of frequency 11 Hertz, hence option e.
The beat frequency (f_beat) is given by the difference in frequency (f) between the two whistles,
f_beat = |f₁ - f₂ |, frequencies of the two whistles are f₁ and f₂ . The frequencies can be calculated from the wavelengths (λ) using the formula,
f = c/λ, speed of sound in air is c, which is approximately 343 m/s at room temperature and atmospheric pressure. For the first whistle with a wavelength of 3.2 m,
f₁ = c/λ₁
= 343/3.2
= 107.1875 Hz
For the second whistle with a wavelength of 2.9 m,
f₂ = c/λ₂
= 343/2.9
= 118.2759 Hz
The difference in frequency is,
f_beat = |f_1 - f_2|
= |107.1875 - 118.2759| ≈ 11.1 Hz
Therefore, the beat frequency is approximately 11 hertz.
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A megaphone amplifies sound by
all the above
increasing the range of frequencies that can be produced.
focusing sound energy into one specific direction.
spreading out the sound waves over a large area.
