Answer is false.
An electromagnetic wave is a non-mechanical wave which does not require a medium for its transmission. This travels even through vacuum. Examples of electromagnetic waves are radio wave, X ray, infra red rays,gamma rays etc.
A mechanical wave requires a medium for transmission. There are three types of mechanical waves namely transverse waves, longitudinal waves and surface waves. Some of the examples of mechanical waves are sound waves,water waves and seismic waves.
Is 2Na + Cl --> 2 NaCl a balanced chemical equation? Is it obeying the law of conservation of matter?
No it is not balanced. It has more CI on the product side that the reactant side.
Hope I helped
Grinding wheat in to flour is a a. physical change b. chemical change Please select the best answer from the choices provided
It is a physical change. One is physically change the wheat from one form to the other.
Which BEST compares the motions of dots C and D?
A) Both C and D are speeding up.
B) Both C and D are moving at a constant velocity.
C) C is speeding up and D is moving at a constant velocity.
D) C is slowing down and D is moving at a constant velocity.
As per the graph there is a motion map which denotes the motion of two dots C and D respectively.
As per the graph the motion of dot C is non uniform .It is so because it is covering unequal distance in equal interval of time.Its speed is increasing at every instant .Hence it is speeding up.
The motion of dot D is uniform .It covers equal distance in equal interval of time.Hence the dot D is moving at a constant velocity.
Hence out of four options given in the question,the third option i.e C is the correct answer .
why is it important to select a coordinate system when studying motion?
Motion is detected when an object changes its position with respect to a reference point. Coordinate system is basically used to represent motion. A coordinate system uses numbers or coordinates which represent position of the reference points on a two-dimensional or three-dimensional space. The trajectory of a point or line can be studied on a coordinate system which describes various aspects of motion like velocity, acceleration, distance, displacement etc. Coordinate system is important because it helps to choose a starting point and the direction (which will be positive).
A particle moving along the y-axis has the potential energy u =4y3j, where y is in m. what is the y-component of the force on the particle at y=0 m, 1 m, and 2 m?
Potential energy is given as
[tex]U = 4y^3[/tex]
now as we know that force is related by potential energy by the formula
[tex]F = - \frac{dU}{dy}[/tex]
So it is gradient of energy with position in Y
[tex]F = - \fracd(4y^3}{dy}[/tex]
[tex]F = -12y^2 \hat j[/tex]
Now at y = 0
[tex]F = 0 N[/tex]
at y = 1
[tex]F = - 12*1^2 [/tex]
[tex]F = - 12 N[/tex]
at y = 2
[tex]F = - 12*2^2[/tex]
[tex]F = - 48 N[/tex]
so above is the forces at given positions
The force on the particle at
[tex]y=0\;\text{is} \;0\;\text{N}\\\\y=1\;\text{is} \;12\;\text{N}\\\\y=2\;\text{is} \;48\;\text{N}\\[/tex]
Explanation:
Given information:
The potential energy: [tex]U=4y^3[/tex]
Now, as we know that force:
[tex]F=-\frac{dU}{dy}[/tex]
So, the gradient of energy with position y
[tex]F=-4y^3dy\\F=-12y^2j[/tex]
At, y=0
[tex]F=0\;N[/tex].
At, y=1
[tex]F=-12+1\\F=-12 \;N[/tex]
At, y=2
[tex]F=-12\times 4\\F=-48\;\text{N}[/tex]
Hence , The force on the particle at
[tex]y=0\;\text{is} \;0\;\text{N}\\\\y=1\;\text{is} \;12\;\text{N}\\\\y=2\;\text{is} \;48\;\text{N}\\[/tex]
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According to symbolic interactionism, which stage of role taking involves individuals beginning to imagine and play the role of a significant other?
The correct stage of role taking according to symbolic interactionism is the play stage.
Symbolic interactionism is a sociological perspective that is influenced by the work of George Herbert Mead. According to Mead, the process of role taking involves several stages through which individuals develop their self-concept and learn to interact with others in society. The stages are as follows:
1. Preparatory Stage (Imitation): In this initial stage, children imitate the behaviors and actions of significant others without fully understanding the roles they are imitating.
2. Play Stage: This is the stage where individuals, often children, begin to imagine and play the role of a significant other. During the play stage, children take on the roles of people in their lives, such as parents, teachers, or other figures, and act out scenarios from their perspective. This imaginative play helps children to understand the roles and expectations of different social positions.
3. Game Stage: In the game stage, individuals start to internalize the generalized other, which represents the organized attitudes of a social group. Here, children learn to consider the expectations of a wider community and how their actions fit into larger social systems. They learn to play games with rules and understand that each role has its own set of expectations and behaviors that are dictated by social norms.
4. Generalized Other: Finally, individuals develop the ability to think from the perspective of the generalized other, which means they can consider the expectations of society as a whole when interacting with others. This stage is crucial for the development of a fully formed self-concept and the ability to engage in complex social interactions.
Thus, the play stage is where individuals begin to imagine and play the role of a significant other, which is essential for the development of empathy, social understanding, and the ability to take on various social roles throughout life.
compare the potential energy of water molecules as water changes from a solid to a liquid
The average kinetic energy of a substance is directly proportional to the temperature of that substance.
[tex]Mathematically\ Kinetic\ energy [K.E]\ \alpha\ T[/tex]
Here T is the temperature.
During the process of change of state,the temperature of the system remains constant as long one substance is not converted into another substance. It means that the energy absorbed or released at that time is utilised in changing the state of substance only. As kinetic energy is constant,so gain or loss of energy is attributed to potential energy.
In the given question,the water is converted from solid to liquid. During the melting of ice, heat is given to the ice for converting into liquid. The energy given is called latent heat which is nothing else than the gain of potential energy of water.
Hence water in liquid form has more potential energy than solid ice.
At the melting point, the solid form of water changes to liquid form. This happens at fixed temperature. During the phase change, the bonds between the molecules break and weakens. This reduces the binding potential energy. There is no change in the translational kinetic energy which is reflected by the temperature being constant during the phase change. The binding potential energy which reduces is actually utilized in breaking of the molecular bonds which eventually causes the phase change.
The same physical quantity, such as density, can be reported using different units. Above, you found that water has a density of 1000kg/m3=1g/cm3 . Because the density of water must be the same regardless of what units you use to measure it, you can conclude that an object whose density is 1 kg/m3 must be less dense than water. In other words, 1 kg/m3 is less than 1 g/cm3 . If you had three different objects with densities of 1 kg/m3 , 1 g/m3 , and 1 kg/mm3 , which object would be the most dense? Rank the given densities from most to least dense. To rank items as equivalent, overlap them.
In the question there are three values of densities.
We are asked to arrange these values in descending order.
In order to solve this problem first we have to convert each values into same unit.Let the unit chosen to be gram per cubic centimeter.
The first value is 1000 kg per cubic metre.
we know that 1 kg=1000 kg and and 1 m=100 cm
Hence the value in CGS system will be-
[tex]1 kg/m^3 =\frac{10^3 gram}{[10^2cm]^3}[/tex]
[tex]=10^-3\ g/cm^3[/tex]
The second value is 1 gram per cubic centimetre.
Third value is 1 kg per cubic millimeter.
we know that
[tex]1 mm =10^-1 cm[/tex]
Hence 1 kg per cubic millimeter i.e
[tex]1 kg/mm^3[/tex]
[tex]=\frac{10^3 gram}{[10^-1cm]^3}[/tex]
[tex]=10^6 g/cm^3[/tex]
Hence the perfect order will be-
[tex]10^6 g/cm^3[/tex] >[tex]1 g/cm^3[/tex] > [tex]10^-3\ g/cm^3[/tex]
[tex]i.e\ 1 kg/mm^3>1\ g/cm^3>1 kg/m^3[/tex]
Answer:
1 kg/mm³, 1 kg/m³, 1 g/m³
Explanation:
We have 3 objects of different densities, 1 kg/m³, 1 g/m³, and 1 kg/mm³.
In order to compare their densities, we will express all of them in the same units, for instance, kg/m³.
First object
It has a density of 1 kg/m³.
Second object
We know that 1 kg = 10³ g. Then,
1 g/m³ × (1 kg/10³ g) = 10⁻³ kg/m³
Third object
We know that 1 m = 10³ mm. Then,
1 kg/mm³ × (10³ mm/1 m)³ = 10⁹ kg/mm³
The densities, from most to least dense are:
1 kg/mm³, 1 kg/m³, 1 g/m³
How is a scientific theory different from a hypothesis? A theory is an explanation of a single phenomenon; a hypothesis is a question that can be tested. B. A theory is a well-tested explanation; a hypothesis is a possible answer that needs to be tested. C. A theory and a hypothesis are both educated guesses, but a hypothesis is not proven. D. A theory explains a scientific law; a hypothesis explains a theory.
its dddddddddddddddddddddddd
This diagram represents a top-down view of an experiment on a table. The 250g and 100g masses are falling and are pulling the block.
What is the location and minimum number of masses that would have to be added to the picture above to cause the block to move only toward the bottom (straight down)?
A. 1000g mass on bottom
B. 500g mass on bottom
C. 250g mass on the left
D. 250g mass on left and 200g mass on bottom
Answer:
C. 250g mass on the left
Explanation:
As the given figure there are two forces on the box placed on the table
1) due to 250 gram there will be a force which will pull it towards right
2) due to 100 g mass which will pull it downwards
now if we wish to move the block only in downward direction then we have to add a force on the block that will counterbalance the force towards right direction
so here it must have a force towards left which will balance the force of 250 g mass towards right
so it would be
C. 250g mass on the left
Corbin, an avid skier leaves the horizontal end of a ramp with a velocity of 33.0 m/s and lands 63.0 m from the base the ramp. How high is the end of the ramp from the ground?
Answer:
Height of ramp = 17.49 m
Explanation:
We have equation of motion , [tex]s= ut+\frac{1}{2} at^2[/tex], s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
Considering horizontal motion of skier
Initial velocity = 33 m/s, Displacement = 63 m, acceleration = 0 and we need to find time taken to reach ground by the skier.
[tex]63= 33t+\frac{1}{2} *0*t^2\\ \\ t=1.909seconds[/tex]
The vertical distance traveled in 1.909 seconds is the height of ramp
Initial velocity = 0 m/s, acceleration = acceleration due to gravity = 9.8 [tex]m/s^2[/tex], time = 1.909 s and we need to find displacement.
[tex]s= 0*1.909+\frac{1}{2} *9.8*1.909^2\\ \\ s=17.49 m[/tex]
So height of ramp = 17.49 m
Why is it important to select a coordinate system when studying motion?
Because this allows us to describe the direction of the motion.
In fact, when studying a motion, we need to specify the velocity of the object, which consists of a magnitude (the speed) and also a direction. Without a coordinate system, it would be impossible to describe in which direction is the object moving.
A person can jump a horizontal distance of 1.57 m on the Earth. The acceleration of gravity is 8.21 m/s 2 . How far could he jump on the Moon, where the free-fall acceleration is 0.153g?
Horizontal distance that a person can jump on the ground is known as horizontal range.
Horizontal range can be calculated by the formula of projectile motion which is given as
[tex]R = \frac{v^2sin2\theta}{g}[/tex]
here for the maximum possible range of jump we can say that he must have to jump at 45 degree
so that the value of the range will be maximum in above equation
[tex]R = \frac{v^2}{g}[/tex]
now if we compare the jump of a person on two planets then as per the capability of the person then velocity of jump will remain same on two planets so we can say
[tex]\frac{R_1}{R_2} = \frac{g_2}{g_1}[/tex]
[tex]\frac{1.57}{R_2} = \frac{0.153g}{g}[/tex]
here it is given that on Earth the acceleration is g = 8.21 m/s^2[/tex]
and on moon it is g' = 0.153g
now we have
[tex]\frac{1.57}{R_2} = \frac{0.153}[/tex]
[tex]R_2 = \frac{1.57}{0.153}[/tex]
[tex]R_2 = 10.3 m[/tex]
So the person can jump a distance of 10.3 m on the Moon
The person could jump about 6.43 times higher on the Moon than on Earth if the takeoff speed is the same in both locations.
Explanation:To find out how much farther a person could jump on the Moon compared to Earth, we need to use the concept of gravitational acceleration. The gravitational acceleration on the Moon is about 1/6 that of Earth. Since the takeoff speed of the astronaut is the same in both locations, we can use the equation: distance = (takeoff speed)^2 / (2 * gravitational acceleration).
Let's say the person can jump a distance of 1.57 m on Earth, with a gravitational acceleration of 8.21 m/s^2. On the Moon, the gravitational acceleration is 0.153 * 8.21 m/s^2. Plugging these values into the equation, the person could jump a distance of approximately 10.09 m on the Moon. This means the person could jump about 6.43 times higher on the Moon than on Earth.
Which tools collect images during space exploration? Check all that apply. rovers orbiters satellites space shuttles space stations
Answer:
1. Rovers- These are vehicles which are designed to move on the surface on any celestial body and collect samples, data and images. Sometimes, these can be used to transport mission crew members.
2. Orbiters- These are spacecrafts designed to orbit any celestial body and collect data in form of images.
3. satellites- artificial satellites are placed in the orbit of celestial bodies for various purposes. There are various types of satellites like communication satellite, weather satellites, space telescopes. These collect images and data inform of signals.
4. space stations: It is a satellite where research and experiments take place. Images are also collected for research purpose.
Space shuttle is a wrong option because it is just a vehicle to transport these satellites and probes into the space and place in the orbit or surface of celestial body.
Answer:
rovers
satellites
space stations
Explanation:
i just took the test
A crate is pulled to the right with a force of 83.6 N, to the left with a force of 121.7 N, upward with a force of 633.6 N, and downward with a force of 241.7 N. What is the net external force in the x direction?
We can assume here that left and right directions are -X and + X directions respectively
Similarly its perpendicular directions are +Y and -Y i.e. upwards and downwards respectively
So here it is given that
[tex]F_1 = 83.6 N[/tex] +X direction
[tex]F_2 = 121.7 N[/tex] - X direction
[tex]F_3 = 633.6 N[/tex] + Y direction
[tex]F_4 = 241.7 N[/tex] - Y direction
Now net force in X direction is required here in this question
So here in X direction there are two forces opposite to each other
so in order to find net force we need to add them vector addition rule
so here
[tex]F_{net} = F_1 - F_2[/tex]
[tex]F_{net} = 83.6 - 121.7[/tex]
[tex]F_{net} = -38.1 N[/tex]
so it requires 38.1 N force towards left
The air sealed between two panes of glass in some windows helps to _____.
reduce the flow of heat passing through the window
increase the flow of heat passing through the window
reduce the visible light passing through the window
increase the visible light passing through the window
The answer is: reduce the flow of heat passing through the window.
A double glazing window or insulating glass consists of two glass window panes separated by a spacer bar and seals to create a hermetically-sealed environment. Space between glass panes is filled under vacuum with either dehydrated air or an inert gas to improve insulation and prevent condensation within the unit. The physical properties of the dehydrated air used in the space between glass panes mean that it transmits less heat than normal air, this is because the molecules of dehydrated air are relatively inert and therefore have a lower thermal conductivity.
The air sealed between two panes of glass in some windows helps to reduce the flow of heat passing through the window. Even though the windows are more expensive to build, that little bit of trapped air in there is a very effective INSULATION. It makes the house easier to keep warm in Winter, and easier to keep cool on Summer, and both of those save on the cost of gas or electricity for the house.
Which of the following best explains how budgeting helps consumers reach their financial goals? A)budgets provide consumers with the product information needed to make well-informed goals. B)Budgets allow consumers to control how much money they have going out for expenses. C)budgets enable consumers to find the lowest prices for the goods and services they need. D)budgets help consumers compete with producers for scarce natural resources.
Budgets help consumers control their expenses and reach financial goals by providing a system to track and manage incoming and outgoing funds, allowing for informed financial decisions.(Option B)
Explanation:The question relates to how budgeting assists consumers in reaching their financial goals. Among the given options, B) Budgets allow consumers to control how much money they have going out for expenses is the best explanation. A budget is an invaluable tool that enables individuals to track incoming and outgoing funds, ensuring that expenses do not exceed income. It helps in identifying non-essential expenditures and allows for adjustments to meet financial goals.
While budgeting isn't always easy—often because it requires making trade-offs and giving up certain pleasures—it is essential in a world of economic scarcity where desires outstrip realities. By creating and adhering to a budget constraint, individuals can navigate their financial resources effectively and make informed decisions about their consumption.
1. A car with a mass of 1,500 kilograms is moving around a circular curve at a uniform velocity of 16 m/s. The curve has a radius of 100 meters. What's the centripetal force on the car?
2. A car with a mass of 1,200 kg is moving around a circular curve at a uniform velocity of 20 m/s. The centripetal force on the car is 6,000 N. What's the radius of the curve?
Write your answers using 1–2 paragraphs.
3. Describe the universal gravitational law.
4. Evaluate the techniques and models used by Ptolemy and Copernicus to explain the setup of the universe.
Answers
1) 3,840 N
2) 80 m
Explanations
Centripetal force is the force that maintenance objects that are moving in a circular motion.
F = mv²/r
= (1500 × 16²)/100
= (1500×256)/100
= 384000/100
= 3,840 N
2) F = (mv²)/r
6000 N = (1200 × 20²)/r
r = (1200 × 400)/6000
= 480,000/6000
= 80 m
Discovered by Sir Isaac Newton, this law states that every object in the universe that has mass attracts every other object in the universe that has mass. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between their centers. When applying this to a situation with two objects, the object with the smaller mass will do most of the moving because the other object has too much inertia to move any noticeable amount.
4. Without advanced technology like we have today, Ptolemy and Copernicus tried to best explain the model of the universe through observation. Ptolemy’s model came first and placed a stationary earth at the center of the model. Everything else moved in respect to earth. This was widely accepted since it seemed like earth was not moving. Ptolemy stated that the planetary bodies moved around the earth in circular paths. However, this wasn’t always witnessed through observation. He adjusted his model to state that some planets must be moving in secondary orbits.
Copernicus put a rotating earth in a sun-centered model. The rotation of earth was able to account for the rising and setting of stars. The orbital motion of the earth and moon also accounted for the motion of the sun and moon with respect to the stars. This was easier to understand but encountered scrutiny due to its differences from religious teachings.
One big difference between the approaches in the two is that Copernicus didn’t try to adjust his model to match what was going on; he used observations to develop the model. In addition, one common trend in science is that the simplest explanation is usually most accurate or closer to accurate. Copernicus’ model was more straightforward; Ptolemy’s was more complex.
While teaching about transistors, Mr. Mendoza shows a video of a hand pump being used to draw water from a well. He points out how the person primes the pump by pouring a small amount of water into it before the water would start to flow. No matter how much water is used to prime the pump, once started, the pump provides a steady flow of water while the handle is operated.
What is Mr. Mendoza using the hand pump to model?
its use as a switch to make a small signal into a large signal
its use as an amplifier to make a small signal into a large signal
its use as a switch to turn on a large current using a small current
its use as an amplifier to turn on a large current using a small current
Mr. Mendoza is using the hand pump to model the transistor's use as a switch to turn on a large current using a small current.
If my teacher had used this model (around 1972) to illustrate the concept, I don't think I would have absorbed the idea. I was substantially clueless, and the model is pretty abstruse.
Mr. Mendoza using the hand pump to model to use it as a switch to turn on a large current using a small current. Hence option C is correct.
What is transistor ?The definition of the Transistor is in name itself, it is the transfer of resistance. it has three terminals collector, base and emitter. Emitter is highly immured which emits the charge charrier. Collector is moderately immured which collects charge carrier and Base which is lightly immured which biases the charge carrier. It is connected in common base, common emitter and common collector mode. Common emitter mode is widely used for amplification and switch purpose.
To use transistor as a switch emitter is grounded and collector is at positive potential. When voltage at the base exceed the cut off voltage(0.7 V for silicon), it drives the current from collector to emitter and whatever instrument is connected to it gets on.
In the picture of the hand pump, tap works as emitter, inlet of the handpump work as collector and handle of the pump work as base which drives the water. Motion in the handled of handpump produces flow of water from ground to tap. it is used as switch.
Hence option C is correct.
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This term means pertaining to or exist at or from the very beginning.
A. Primordial
B. Accretion
C. By-product
D. Homogeneous
A sailboat starts from rest and accelerates at a rate of 0.13 m/s2 over a distance of 458 m.
(a) Find the magnitude of the boat's final velocity.
m/s
(b) Find the time it takes the boat to travel this distance.
s
Given:
u(initial velocity): 0
a(acceleration): 0.13 m/s∧2
distance = 458 m
Now s= ut +1/2 (at∧2)
Substituting from the given values we get
458= 0+ 1/2(0.13 x t∧2)
t = 83.94 secs
Now v (velocity)= u+ at
Substituting for t as 83.94 secs and for a and u from the given values we get:
v= 0+0.13 x t
v= 0.13 × 83.94
v=10.91 m/s
Therefore the final velocity of the boat is 10.91 m/s and the time taken for the boat to travel 458 m is 83.94 secs
If you know the distance of an earthquake epicenter from three seismic stations, how can you find the exact location of the epicenter of the earthquake.
You draw 3 circles around the stations with the size of the circle equal to the distance from the earthquake. Then you simply find where the edge circles all overlap.
A toaster uses 400 W of power. How much energy does it use in 5 seconds? A. 2000 J B. 1000 J C. 80 J D. 400 J
A
Energy = Power × time
= 400 × 5 = 2000 J
In 5 seconds, the toaster uses 2000 joules (J). The Choice (A) 2000J is the best one.
Given:
Power of the toaster (P) = 400 W
Time (t) = 5 seconds
The quantity of work completed or the entire amount of power used over a specific time period is referred to as energy (E). In the International System of Units (SI), it is expressed in joules (J). The energy calculation formula is as follows:
For the energy used by the toaster in 5 seconds,
Energy (E) = Power (P) × Time (t)
E = 400× 5
E = 2000 joules (J)
Therefore, the toaster uses 2000 joules (J) of energy in 5 seconds. The correct answer is A. 2000 J.
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What is the value of the impulse obtained from the graph?
C) 9 kilogram meters/second
Explanation:
The impulse is defined as the integral of the force over the time:
[tex]J=\int F dt[/tex]
in a force-time graph, the impulse corresponds to the area under the curve. Therefore, in this case we can calculate the impulse by finding the area of the triangle.
The base is 3 s, while the height is 6 N, therefore the area (and the impulse) is
[tex]J=\frac{(3 s)(6 N)}{2}=9 kg m/s[/tex]
Answer:
C) 9 kilogram meters/second
Explanation:
Correct answer on plato/edmentum
What are base isolators and give an example of an earthquake proof building
Base isolation is a technique developed to prevent or minimise damage to buildings during an earthquake. It has been used in New Zealand, as well as in India, Japan, Italy and the USA.
Taipei 101
Astronomers want to study a star in the Andromeda galaxy, the closest galaxy to our own. Which instrument has the advanced technology needed to study such a far-off object? Check all that apply. rover probe satellite space station space observatory
Answer:
Probe, Space Observatory
Explanation:
A probe can be sent off to far away planets and galaxies. A space observatory is an outer space observatory with an advanced telescope used to study the universe.
To study a star in the Andromeda galaxy, astronomers use satellites and space observatories equipped with advanced telescopes and detectors. Rovers, probes, and space stations are not used for studying distant galaxies.
Explanation:Astronomers who wish to study a star in the Andromeda galaxy, the closest galaxy to our Milky Way, would require highly advanced technology due to the vast distance involved—about 2.5 million light-years from Earth. The instruments capable of such observations include satellites and space observatories. These are equipped with large telescopes and sensitive detectors that can capture images and spectra of distant galaxies, despite their faint appearance due to the immense distance. Observatories like the Hubble Space Telescope have been instrumental in exploring objects in distant galaxies. Rovers and probes are primarily designed for in-situ exploration of objects within our solar system, such as planets, moons, and asteroids, and would not be used to study distant stars. Similarly, space stations like the ISS serve as research labs for experiments in microgravity and would not be used for distant astronomical observations.
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Boris puts ice cubes into a glass of water. The ice cubes begin to melt becauseA: the water gains heat energy from the ice cubes. B: the ice cubes gain heat energy from the water.C:the warm air around the glass changes the temperature of the ice cubes. D:the molecules in the ice cubes are moving faster than the molecules in the water.
B: the ice cubes gain heat energy from the water.
Medical equipment uses ultrasound to process images using _________. resonance
the Doppler effect
constructive interference
destructive interference
The medical equipment used for ultrasound imaging is based on Doppler's effect.
The ultrasound imaging process uses high frequency radio waves to view inside images like tendons,muscles,joints,blood vessels etc.
In this process the transmitted pulse produces a Doppler's shift when it interacts with the moving reflector. Here we have to consider the moving reflector as the moving source.The moving reflector will produce an echo which will be received by the transducer.The transducer acts as stationary observer.
The whole process can be explained as below-
1-The ultrasound machine transmits the high frequency signal to the body through a prove.The sound will be reflected by the boundary of tissue and received by the probe.Some sound waves penetrate more into inside part of the body.
2-The received reflected sound will be allowed to enter into the machine which calculates the distance between various tissue and forms an image based on Doppler's shift.
Hence the correct answer is Doppler's effect.
Answer:
the Doppler effect
Explanation:
The frequency of the sound waves used in Doppler ultrasound are high frequency sound waves. These are used to observe and measure the amount of blood that is flowing through the arteries and veins . The veins that supply the blood to arms and legs are studied using the Doppler ultrasound technology.
The ultrasound waves can accurately measure the movement of the red blood cells, since their movement can produce a change in the frequency of the sound waves that are reflected.
Your forehead can withstand a force of about 6.0 kn before fracturing, while your cheekbone can withstand only about 1.3 kn. suppose a 140 g baseball traveling at 30 m/s strikes your head and stops in 1.5 ms.
a. what is the magnitude of the force that stops the baseball?
b. what force does the baseball exert on your head? explain.
c. are you in danger of a fracture if the ball hits you in the fore- head? on the cheek?
a) The change in momentum of the ball is given by:
[tex]\Delta p = m \Delta v[/tex]
where m=140 g=0.14 kg is the mass of the ball, and [tex]\Delta v =30 m/s[/tex] is the change in velocity. Substituting, we find
[tex]\Delta p=(0.14 kg)(30 m/s)=4.2 kg m/s[/tex]
The ball stops in t=1.5 ms=0.0015 s; the magnitude of the force that stops the baseball is given by the ratio between the change in momentum and the time taken:
[tex]F=\frac{\Delta p}{t}=\frac{4.2 kg m/s}{0.0015 s}=2800 N=2.8 kN[/tex]
b) The force we found at point a) is the force that the head exerts on the ball to stop it. However, Newton's third law states that when an object A exerts a force on an object B, object B also exerts a force equal and opposite on object A. If we apply this law to this case, we understand that the force exerted by the baseball on the head is equal to the force exerted by the head on the ball: therefore, the answer is still 2.8 kN.
c) The forehead is not in danger of a fracture, since it can withstand a maximum force of 6.0 kN, while the ball exerts a force of 2.8 kN. Instead, the cheek is in danger of fracture, because it can withstand only a maximum force of 1.3 kN.
Which of the following is true about all of the outer planets?A.Much of the material in these planets is solid.B.The surface of these planets is rocky.C.They have many moons.D.They all rotate in the same direction.