4. Solid ‘X’ turns into a liquid at 80 0C and into a gas at 140 0C. Describe the changes in the
particles of X when it is heated from

a. 70 0C to 85 0C

Answer: C. The critical angle is less than 47°.

Explanation:

The critical angle is the angle such that the refracted beam is parallel to the surface of the prism, so we will have total internal refraction

This comes from the snell law:

n1*sen(a1) = n2*sen(a2)

where n1 is bigger than n2.

Then:

sen(a1) = (n2/n1)*sin(a2)

n2/n1 is smaller than 1, so the right side only can go up to (n2/n1)*1 (when a2 = 90°)

sen(a1) = n2/n1

this equation defines our critical angle.

If we use an angle bigger than the critical angle, we still have a total internal reflection, so we will no see a refracted beam.

In the image, we can see that the angle between the beam and the normal to the surface of the prism is 47°, and we also can see that we have a refracted beam, this means that 47° must be smaller than the critical angle.

So the correct option is C.

Answer:

B. The critical angle is greater than 47°.

Explanation:

Explanation: Light is reflected back into a prism whenever the angle of incidence is greater than the critical angle. When the angle of incidence is less than the critical angle, the light refracts as it exits the prism. In this case, the violet light is refracted as it exits the prism, so the critical angle must be greater than 47°. Also, you can conclude that all other colors of visible light will be refracted as it exits the prism. Shorter wavelengths (at the violet end of the spectrum) are the "first" to be reflected. If violet light is not reflected, then no visible light will be reflected.

Answer:

The coefficient of kinetic friction is [tex]\mu_k = 0.07.[/tex]

Explanation:

Let us call [tex]F_k[/tex] the force of friction, then we know that [tex]220N - F_k[/tex] is what has caused the acceleration [tex]a =3m/s^2[/tex]:

[tex]220-F_k =ma[/tex]

[tex]220-F_k =(60kg)(3m/s^2)[/tex]

[tex]220-F_k =180[/tex]

[tex]F_K = 40N[/tex]

Now this frictional force relates to the coefficient of kinetic friction [tex]\mu_k[/tex] by  

[tex]F_k = \mu_k N[/tex]

where [tex]N=mg[/tex] is the normal force.

Putting in numbers and solving for [tex]\mu_k[/tex] we get:

[tex]\mu_k = \dfrac{F_k}{mg}[/tex]

[tex]\mu_k = \dfrac{40N}{(60kg)(10m/s^2)}[/tex]

[tex]\boxed{\mu_k = 0.07}[/tex]

Hence, the coefficient of kinetic friction is 0.07.

To find the coefficient of kinetic friction, we can set up an equation using the net force, the applied force, and the normal force. Solving for the coefficient of kinetic friction, we find it to be approximately 0.68.

To find the coefficient of kinetic friction between the block and the ground, we need to consider the forces acting on the block. The force of friction opposes the applied force and is equal to the coefficient of kinetic friction multiplied by the normal force. The normal force is equal to the weight of the block, which is 60 kg multiplied by the acceleration due to gravity (9.8 m/s^2).

From the given information, the block accelerates at 3 m/s^2 to the left. Using Newton's second law (F = ma), we can calculate the net force acting on the block. The net force is equal to the applied force minus the force of friction.

Since the block is accelerating to the left, the net force is in the same direction as the applied force. Therefore, the net force is equal to the applied force minus the force of friction. Setting up the equation: F - μkN = ma. Rearranging the equation, we can solve for the coefficient of kinetic friction μk.

μk = (ma + F)/N = (60 kg * 3 m/s^2 + 220 N)/(60 kg * 9.8 m/s^2)

Plugging in the given values:

μk = (180 N + 220 N)/(588 N) = 400 N / 588 N ≈ 0.68

Answer:

waning gibbious

Explanation:

The Mandela effect is a good example of time travel

The Mandela effect is a  false memory effect occur when many different people incorrectly remember the same thing.

It is widespread and it is a false memory by Nelson Mandela, South African human rights activist, an eventual president, died in prison in the 1980s.

When a group of people misremembers the Mandela effect is occurred, it is a  historical event or person.

Nelson Mandela did not die in prison in the 1980s. After serving 27 years in prison, Mandela became president of South Africa from 1994–1999. He died in 2013.

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Kinetic energy only exist if object has motion.

At point 3 , kinetic energy is highest.

We know that,  

                              Kinetic energy  =  [tex]\frac{1}{2} mv^{2}[/tex]

Where m is mass of pendulum and v is speed of pendulum.

Since the mass of the pendulum  would not  change, the only way for kinetic energy to change is for the speed of the pendulum to change.

Kinetic energy is highest when the velocity is the highest. This occurs at the bottom of the pendulum.

At the lowest point (Point 3 ) the pendulum has its greatest speed.  All of the energy in the pendulum is kinetic energy and there is no gravitational potential energy.

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Answer:

its unit is Ohm

Explanation:

Resistance means material which resist the passing current  through it and the value of resistance says how much the material is resisting the current and it temperature dependent and the unit is Ohm.

Answer:

TRUE

Explanation:

A binary star is a star system consisting of two stars orbiting around their common barycenter. Systems of two or more stars are called multiple star systems.

Answer:

True

Explanation:

Answer: The absolute value of the mutual force between the two point charges is 5.3952 x 10^-3 N.

Explanation:

The mutual force between two point charges can be calculated using Coulomb's law, which states that the force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them:

F = k * (q1 * q2) / r^2

where F is the force, k is Coulomb's constant (9.0 x 10^9 N m^2/C^2), q1 and q2 are the charges of the two-point charges, and r is the distance between them.

In this problem, q1 = 9.2 E-6 C, q2 = 3.5 E-6 C, and r = 3 E-2 m. Substituting these values into Coulomb's law, we get:

F = (9.0 x 10^9 N m^2/C^2) * [(9.2 E-6 C) * (3.5 E-6 C)] / (3 E-2 m)^2

F = 5.3952 x 10^-3 N

The absolute value of the mutual force between the two point charges is 5.3952 x 10^-3 N.

Answer:

The heat capacity of the sample of metal is 664j/kg.°C

Explanation:

Kindly find attached a detailed solution to this question for you reference.

Given data

Mass of sample m1= 0.45kg

Temperature of sample θs= 80°c

Mass of water mw = 0.7kg

Temperature of water θw= 15°C

Specific heat capacity of water Cw=

4200j/kg.°C

Equilibrium Temperature θ3= 21°C

HEAT LOSS BY SUBSTANCE =HEAT GAINED BY WATER

What is Quantity of heat?

Quantity of heat is the amount of heat absorbed or given out by a body Q=mcθ

What is the heat capacity?

Heat capacity is the amount of heat required to raise the temperature of a substance by 1k.The S.I unit is joule per Kelvin J/k

What is specific heat capacity?

The specific heat capacity is the amount of heat required to raise the temperature of 1kg of substance by 1k

velocity describes speed with direction.

The difference between speed and velocity is that velocity describes the speed with direction. Hence, option A is correct.

Despite their similarities, speed and velocity have quite different meanings, just as distance and displacement do. Speed, which is a scalar quantity, is the "speed at which an object is moving." The rate at which an object travels a distance can be thought of as its speed.

A fast-moving object travels at a high speed and completes a significant distance in a brief period. This is in contrast to an object traveling slowly, which travels a relatively short distance in the same length of time. Zero speed refers to an object that is not moving at all.

One side velocity is vector and speed is scalar other side.

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Answer:

C. Rub two things together.

Explanation:

Rubbing two things together causes friction which forms energy and there you have it, static electricity. Take a fuzzy sweater and rub it against another fuzzy sweater and then touch it. The energy stored will release in the form of shock.

Answer:

2Hz

Explanation:

Hope this helps

Answer:

c

Explanation:

The correct option is C. They created a closed circuit to attract paper clips using a copper wire coiled around an iron nail. The copper wire was also touching both the positive and negative poles of a D- Battery.

A permanent magnet's magnetic flux constantly flows from its N-pole to its S-pole.

The magnetic field and the current combine to produce force when a conductor is placed in a magnetic field and current passes through the conductor. "Electromagnetic force" is the name of the force.

The direction of the magnetic force, the flux, and the current are all determined by the fleming's left hand rule.

Therefore, The correct option is C. They created a closed circuit to attract paper clips using a copper wire coiled around an iron nail. The copper wire was also touching both the positive and negative poles of a D- Battery.

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Answer:

Photosynthetic organisms

Explanation:

The electromagnetic energy of sunlight is converted to chemical energy in the chlorophyll-containing cells of photosynthetic organisms. In eukaryotic cells these reactions occur in the organelle known as the chloroplast

Hope this helps! :)

Answer:

The producers

Explanation:

Answer:

80 angle of incidence=angle of reflection

Explanation:

Answer:

80 angle of reflection!

Explanation:

Because it is a flat, smooth surface it will reflect like that of a normal plane mirror, so the angle of reflection will be equal to that of the angle of incidence!

Hope this helps you understands!

Answer:

forest rual area

Explanation:

because thats where i live

Final answer:

The desert environment of the Great Basin Desert where I live impacts the city's architecture, economy, and conservation efforts. Unique flora and fauna, along with minimal water resources, shape the community's way of life and urban planning. Geographic features like nearby mountains further influence the city's development and residents' daily activities.

Explanation:

The area in which I live is a desert, specifically the northern tip of the Great Basin Desert. The natural setting of a city can vastly influence its history, design, layout, and way of life. For instance, the dry and semiarid climate of this area has led to a fragile ecosystem. Three examples of how the environment has shaped my city include the architecture, which is designed with materials suitable for hot and dry conditions; the city's economy, which is likely to be based on industries that can thrive in such a climate, such as tourism; and conservation efforts, which are significant due to concern for the fragile ecosystem and endangered species in the region.

This desert environment means we have a unique set of flora and fauna adapted to the dry conditions. Construction materials tend to reflect the limited resources available, leaning more into minimalist designs that can maintain cooler indoor temperatures. The economy is also shaped by the environment, as agricultural practices and water usage have to be carefully managed, and recreational activities often revolve around the unique landscape, such as hiking in desert parks.

The surrounding landscape is characterized by low rainfall and limited water sources, which also impacts urban planning regarding water usage and storage. Additionally, geographic features such as nearby mountains can influence weather patterns and therefore impact city planning and daily life.

Answer:

B)

Explanation:

Aside from his numerous inventions, Galileo also laid down the first accurate laws of motion for masses. Galileo measured that all bodies accelerate at the same rate regardless of their size or mass.

Answer:

Galileo and kepler

Explanation:

Aside from his numerous inventions, Galileo also laid down the first accurate laws of motion for masses. Galileo measured that all bodies accelerate at the same rate regardless of their size or mass.

Answer:

5 m/s

Explanation:

The speed of a wave in a string is related to the tension in the string by the equation

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

where

v is the speed of the wave

T is the tension in the string

[tex]\mu[/tex] is the linear density of the string

We can rewrite the equation as

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

In this problem, the tension in the string is changed; however, its linear mass density remains constant. So we can write:

[tex]\frac{\sqrt{T_1}}{v_1}=\frac{\sqrt{T_2}}{v_2}[/tex]

where:

T1 = 40 N is the initial tension in the string

v1 = 10 m/s is the initial speed of the wave

T2 = 10 N is the final tension in the string

Solving for v2, we find the final speed of the wave:

[tex]v_2=v_1 \sqrt{\frac{T_2}{T_1}}=(10)\sqrt{\frac{10}{40}}=5 m/s[/tex]

Answer:

Speed of the sound in air is 325 m/s

Explanation:

As we know that the frequency of the sound is given as

[tex]f = 25000 Hz[/tex]

wavelength of the sound is given as

[tex]\lambda = 0.013 m[/tex]

now we have

[tex]v = \lambda f[/tex]

so we have

[tex]v = (0.013)(25000)[/tex]

[tex]v = 325 m/s[/tex]

Final answer:

The speed of the sound produced by a dog whistle with a frequency of 25,000 Hz and a wavelength of 0.013m is 325 m/s.

Explanation:

The speed of a sound wave can be calculated using the relationship speed = frequency times wavelength. Given a whistle that produces a sound with a frequency of 25,000 Hz and a wavelength of 0.013m, we can find the speed of this sound wave in air. By multiplying the frequency by the wavelength, 25,000 Hz  imes 0.013m, we get 325 m/s. Therefore, the speed of the sound produced by the whistle is 325 m/s.

Answer:

60m/s

Explanation:

v=s÷t

75m÷1.25s=60m/s

Answer

60

Explanation:

This is because if the question gives you the distance and the time, you have to find the speed.

Answer:

Correct answer: Third statement  P = 4900 W

Explanation:

Given:

m = 500 kg  the mass of the elevator

h = 10 m  reached height after t = 10 seconds

P = ? power of the motor

The formula for the calculating power of the motor is:

P = W / t

since work is a measure of change in this case of potential energy then it is:

W = ΔEp = Ep - 0 = Ep

In this case we must take g = 9.81 m/s²

Ep = m g h = 500 · 9.81 · 10 = 49,050 W ≈ 49,000 W

Ep ≈ 49,000 W

P = Ep / t = 49,000 / 10 = 4,900 W

P =4,900 W

God is with you!!!

Final answer:

The question involves analyzing a position vs. time graph to determine the object's starting position at 3 meters and its velocity, which is calculated as 3 m/s based on the slope of the line.

Explanation:

The question pertains to analyzing a position vs. time graph of an object in motion to determine its starting position, velocity, and other characteristics of its motion. Given the description of a graph where a straight blue line runs with an upward slope from 0 seconds at 3 meters to 4 seconds at 15 meters, we can infer several key details about the object's movement.

The starting position of this object is 3 meters. This is inferred from the graph's indication that at 0 seconds, the object is at 3 meters.

The object is traveling at a velocity calculated from the slope of the line on the position vs. time graph. The velocity can be found using the formula velocity = (final position - initial position) / (final time - initial time). Substituting the given values, velocity = (15 meters - 3 meters) / (4 seconds - 0 seconds) = 12 meters / 4 seconds = 3 m/s.

This scenario highlights the concepts of initial position, velocity, and the relationship between slope on a position vs. time graph and the velocity of an object in motion.

the instantaneous speed at 2 seconds is **0 m/s** since the position remains constant, and the average speed over the entire trip is **1 m/s** based on the information provided by the position-time graph.

To determine the instantaneous speed at 2 seconds and the average speed over the entire trip from the given position-time graph with three straight segments, we can analyze the information provided. Here's how we can approach this:

1. **Instantaneous Speed at 2 Seconds**:

- Since the graph provides position values at specific time points, we can find the instantaneous speed at 2 seconds by looking at the slope of the graph at that point.

- At 2 seconds, the position is not explicitly given. We can infer it based on the straight segments. The position remains constant at 12 meters from 4 seconds to 6 seconds.

- Therefore, at 2 seconds, the position is 12 meters. To find the instantaneous speed, we need to calculate the slope of the line connecting the points at 2 seconds and a nearby point, which is 4 seconds.

- The change in position is 12 meters - 12 meters = 0 meters (since the position remains constant), and the change in time is 4 seconds - 2 seconds = 2 seconds.

- As a result, the instantaneous speed at 2 seconds is 0 meters per 2 seconds = **0 m/s**.

2. **Average Speed over the Entire Trip**:

- The average speed over the entire trip can be calculated by dividing the total distance traveled by the total time taken.

- The object travels from 0 meters to 12 meters (12 meters) and then back to 0 meters (12 meters total distance). The total time taken is 12 seconds (0 to 12 seconds).

- Therefore, the average speed over the entire trip is 12 meters / 12 seconds = **1 m/s**.

In summary, the instantaneous speed at 2 seconds is **0 m/s** since the position remains constant, and the average speed over the entire trip is **1 m/s** based on the information provided by the position-time graph.

The probable question maybe:

A graph titled Position versus time for with horizontal axis time (seconds) and vertical axis position (meters). The line runs in 3 straight segments from 0 seconds 0 meters to 4 seconds 12 meters to 6 seconds 12 meters to 12 seconds 0 meters.

Use the graph to determine the instantaneous speed at 2 seconds.

m/s

What is the average speed over the entire trip?

Answer:

It is not as windy now as it was a little while ago

Slackening wind indicates that the wind speed or intensity is decreasing, meaning it is not as windy now as it was a little while ago.

When we say that the wind is slackening, it means that the speed or force of the wind is decreasing or getting weaker. It suggests that it is not as windy now as it was a little while ago. A slackening wind does not necessarily mean that the wind is now mixed with rain and sleet, nor does it automatically mean that the wind is creating dangerous driving conditions. It solely relates to the intensity or force of the wind which is lowering.

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Answer:

I think that's more of an opinion

Answer:

Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density. ... Hot water is less dense and will float on room-temperature water. Cold water is more dense and will sink in room-temperature water.

Explanation:

Temperature influences a material's density by altering its particles' arrangement; generally, substances expand and become less dense at higher temperatures.

Temperature affects the density of a material due to changes in its molecular structure and particle motion. When a material is heated, its particles gain energy and move more vigorously, causing them to expand and increase the volume they occupy. If the mass remains constant while the volume increases, the density decreases.

This phenomenon is observed in most substances, especially gases and liquids. In contrast, some materials exhibit unusual behavior. For instance, water reaches its maximum density at approximately 4 degrees Celsius before expanding as it freezes into ice. This behavior is essential for aquatic life during winter as it prevents lakes and rivers from freezing entirely, maintaining a liquid layer on the surface. Overall, temperature-induced changes in particle arrangement and motion play a significant role in altering a material's density, impacting various natural processes and industrial applications.

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Answer:

Potential energy decreases because temperature is measured by the how fast molecules move. The more kinetic energy in the molecules, the less potential energy

Answer:

false

Explanation:

Answer: the other guy does not know anything about science! he is incorrect, the answers are past for the first blank and light for the second blank. depending on what planet in space you take pictures on, and how far away they are, and their orbit, it is past and light. because it takes time for light to reach earth depending on the planet's orbit, and how far away it is.

so the correct answers are: past, and light.