Determine the density of a rectangular piece of concrete that measures 3.7 cm by 2.1 cm by 5.8 cm and has a mass of 43.8 grams.

The answer is CFC – 22 or HCFC - 22. To locate leaks, it is easily accomplished using a pressure – regulated dry nitrogen charge with CFC – 22. But some technicians prefer to use Refrigerant – 22 (HCFC – 22) to pressurize the system without the use of nitrogen. CFC – 22 is also known as Chlorodifluoromethane. This is a hydrochlorofluorocarbon (HCFC). This is better recognized as HCFC-22, or R-22. It is usually used as a propellant and refrigerant. While HCFC – 22 is also known as class II hydrochlorofluorocarbon refrigerant that is less harmful to the ozone than R -12. If HCFC – 22 is used for leak testing, all refrigerant must be first detached from the system. After the leak test, HCFC – 22 should be remove before putting any other refrigerant. Do not mix refrigerants. Both HCFC – 22 and R -134a fall into the kind of refrigerants known as combustible. If exposed to oxygen, they will burn when under pressure or exposed to high temperatures. 

The bridge surface can freeze before adjoining road surfaces do because of the difference in heat transfer. The bridge loses heat faster due to exposure to the cold air from above and below, while the roads are insulated by the ground.

The reason why a bridge surface can freeze before adjoining road surfaces do is due to the difference in heat transfer.

When it is cold outside, the bridge surface is exposed to the cold air from above and below, causing it to lose heat rapidly. On the other hand, the adjoining road surfaces are in contact with the ground, which acts as an insulator and slows down the heat loss.

As a result, the bridge surface reaches the freezing temperature faster than the adjoining road surfaces, leading to the formation of ice on the bridge while the roads remain clear.

A turtle crawls and covers a distance of 4.77 m in a time of 19.5 seconds, then the velocity of the turtle will be equal to 0.245 m/s.

Velocity is the rate of change of a traveling object's direction, as measured by a certain unit of time and as seen from a specific vantage point. Speed is a basic concept in kinematic, the branch of special relativity that studies how bodies move.

A scientific vector quantity called velocity must have both a magnitude and direction to be described.

As per the given data provided by the question,

The distance traveled by the turtle, d = 4.77 m

Time is taken by the turtle, t = 19.5 seconds.

[tex]Velocity(v) = Distance(d)/Time(t)[/tex]

v = 4.77/19.5

v = 0.245 m/s.

Therefore, the velocity of the turtle is 0.245 m/s.

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Final answer:

To find the force holding a spring stretched at 11 cm, the spring constant is first calculated using the work done to stretch the spring. The spring constant is found to be approximately 330.58 N/m. The force is then calculated as 36.36 N.

Explanation:

The question relates to calculating the force that holds a spring stretched at a particular distance, given the work done to stretch the spring. The work to stretch (or compress) a Hooke's law spring by a displacement x  is 0.5kx², where k is the spring constant, and x is the displacement. We know that 2 joules of work is done to stretch the spring 11 cm; we can use this information to calculate the spring constant and then find the force.

First, we convert 11 cm to meters by dividing by 100 to get 0.11 meters. Then, rearrange the spring work formula to solve for k:
W = 1/2 k x^2
2 = 1/2 k (0.11)^2
k = (2 * 2) / (0.11)^2
k = 4 / 0.0121
k = approximately 330.58 N/m

Once we have the spring constant, we can calculate the force that the spring exerts when stretched 11 cm:

F = k x
F = 330.58 N/m * 0.11 m
F = 36.36 N

Therefore, the force that holds the spring stretched at 11 cm is 36.36 N.

Resistance is directly propotional to the length of the wire. It is denoted by R. By shortening the wire the value of resistance is decreased in the wire.

The flow of current is due to the flow of charge in the wire. Resistance causes an opposition force in the flow of the current due to which the flow of current got reduced.

Hence resistance is inversly propotional to the value of the flow of current.

If the length of the wire, the cross-sectional area of the wire, and resistivity of the material are known, the resistance of the wire may be computed as follows:

[tex]\rm R=\frac{\rho l}{A}[/tex]

R is the resistance,

is the wire's resistivity

L is the wire's length

A is the area of a crosssection of the wire.

From the above formula, we get the resistance is directly propotional to the length of the wire.

Hence by shortening the wire the value of resistance is decreased in the wire.

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Answer:

its d

Explanation:

Answer:

Crust and Upper Mantle

Explanation:

I am just so smart

Answer:

B.An electromagnetic field interacts with charged particles.

Explanation:

As we know that electromagnetic field is the combination of electric field and magnetic field both.

If the electric field or magnetic will interact with charge particle then due to interaction of charge particles with the field there is force on the charge particle which is given as

for electric field

[tex]F = qE[/tex]

for magnetic field

[tex]F = q(v \times B)[/tex]

so in both cases the charge particle will have interaction with magnetic field or electric field

so correct answer would be

B.An electromagnetic field interacts with charged particles.

Electromagnetic force occurs when an electromagnetic field interacts with charged particles. The correct option is (B).

When charged particles interact with an electromagnetic field, electromagnetic force results. Along with gravity, the weak nuclear force, and the strong nuclear force, this force is one of the four fundamental forces of nature.

Electric charges or electric currents cause an electromagnetic field to form. When charged particles, such as electrons or protons, are near an electromagnetic field, the interaction between their charge and the field causes them to feel a force.

The electromagnetic force is given by:
F = q(E + v×B)

Many commonplace phenomena and technology applications are fundamentally influenced by electromagnetic force. It is in charge of numerous electromagnetic phenomena, including interactions between charged particles, electrical circuit behavior, the creation of magnetic fields, and many more.

Hence, electromagnetic force occurs when an electromagnetic field interacts with charged particles. The correct option is (B).

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Answer: all colors

.......

Valerie is preparing a blood sample for analysis. For this purpose, a machine called a centrifuge is used which spins the blood sample to separate the red blood cells, platelets and plasma from blood. As the blood is separated, the heavier reds cells sink to the bottom of the tube and are given back to the person.

A test done on a sample of blood is used to measure the amount of certain substances in the blood or to count the different types of blood cells present in the blood sample. Blood tests may be done to look for the signs of disease or agents which cause disease, to check for the antibodies or tumor markers, or to see how well the different treatments are working.

Valerie is preparing a blood sample for the purpose of analysis. First, she should put the blood sample in a test tube and place it in a centrifuge machine. This machine would cause the red blood cells from the blood to move to the bottom of the tube because of their higher density in comparison to other components. Next, Valerie would be able to decant the plasma from the blood and analyze it separately from the red blood cells.

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Answer:

PWC operators can minimize annoying noise using destructive interference, where a second sound with maxima and minima exactly opposite the incoming noise is introduced. This resulting sound is much quieter. This technique can also apply engineering changes to parts that could resonate at the annoying sound frequency.

PWC operators can minimize annoying noise using a method based on sound interference, notably destructive interference. Figure 17.23 provides a demonstration with headphones that use this principle to cancel noise. The main idea of noise cancellation is to introduce a second sound with its peaks and troughs exactly opposite from the incoming noise. This is achieved through a fast electronic analysis. The two sounds then interfere destructively, resulting in a much quieter sound.

Achieving completely destructive interference in practice is rarely possible, but using this method, it's feasible to reduce noise levels by 30 dB or more. Notably, the principle of Pascal's principle is at play, where pressures from two different sources add and subtract like simple numbers. This results in a lower-intensity sound, i.e., less noise.

This technique can be extended to include studying parts that could resonate at the frequency of the annoying sound, and then engineering changes to eliminate that resonance. It may involve changing the material used or changing the length of the part, as discovered in Fourier Analysis.

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Option A: The skier has potential and kinetic energy

 To solve this problem, let us first assume that the hydrogen gas acts like an ideal gas. So that we can make use of the ideal gas equation:

P V = n R T

where P is the pressure, V is the volume, n is the number of moles, R is the universal gas constant and T is the absolute temperature

Since it is given that T and P is constant therefore we can write the equation as:

V / n = k

So equating the two conditions:

V1 / n1 = V2 / n2

We can now solve for the new V2 given n2 = 0.125:

2 L / 820 mol = V2 / 0.125 mol

V2 = 3.05 x 10^-4 L

The new volume is about 3.05 x 10^-4 L which is equivalent to 0.3 mL

Answer:

Increase of temp causes the rate of a reaction to increase, which increases the kinetic energy of molecules, causing more collisions

To determine how high a baseball goes and how long it is in the air when hit straight up, we use kinematic equations. The maximum height is given by the formula h = V_i^2 / (2g), and the total time in the air is calculated by t = (2V_i) / g.

A baseball hit straight up into the air with a speed of 22 m/s undergoes uniform accelerated motion due to gravity, which is -9.81 m/s2. To determine how high the baseball goes, we use the kinematic equation h = Vi2 / (2g), where Vi is the initial velocity and g is the acceleration due to gravity. Substituting 22 m/s for Vi and 9.81 m/s2 for g, we can calculate the maximum height the ball reaches.

For part (b), calculating how long the baseball is in the air, we use the kinematic equation t = (2Vi) / g, considering the ball has to go up and then come down, doubling the time it takes to reach the maximum height (as the initial speed going up is the same as the final speed coming down, just with opposite signs).

These equations and methods apply similarly to all projectile motion problems and are useful to address multiple exercises including the determination of initial velocity, time in the air, and maximum height in various scenarios such as a ball kicked with initial components, the range of projectiles, the work done by air resistance, and more.

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The correct matches are:

1. obsidian - B) extrusive igneous;

2. granite - A) intrusive igneous;

3. conglomerate - C) clastic sedimentary;

4. evaporite - E) chemical sedimentary;

5. coal - D) organic sedimentary;

6. marble - F) metamorphic;

There are three big groups of rocks, igneous, sedimentary, and metamorphic. They further diversify into multiple types of rocks in accordance to their structure, chemical composition, crystallization, formation etc. The igneous can simple be divided into intrusive (ones that formed on the surface or very close to it) and extrusive (ones that formed deep into the ground). The sedimentary rocks can be divided into multiple groups in accordance to their composition, as some can be made of multiple sediments, some from organic material, some from mixture of sediments and organic material etc. And the metamorphic can simply be seen as rocks that come to be as a result of the transformation of the other two types if they are under big pressure and temperatures for longer periods of time.

Answer:

To find initial velocity in projectile motion without the angle, use the vertical motion information to calculate time of flight, then use horizontal distance and time to find horizontal velocity, and combine it with initial vertical velocity using the Pythagorean theorem.

To find the initial velocity in projectile motion without knowing the angle, one approach is to use the given vertical motion information. According to the provided discussion, if a projectile has an initial vertical velocity (Vy0) of 14.3 m/s and lands 20.0 m below its starting altitude, the time of flight is 3.96 seconds. This time is solely determined by the vertical motion, as the vertical acceleration is constant due to gravity.

Once the time of flight is known, you can calculate the horizontal component of the velocity (Vx) as follows: Vx = horizontal distance traveled / time of flight. It is important to note that Vx is constant throughout the motion if air resistance is negligible. The horizontal component can then be used in combination with the vertical component to calculate the total initial velocity (Vo). This can be done by using the Pythagorean theorem, Vo = √(Vx² + Vy0²).

The best answer for this question would be:

 The onset of World War II 

It started during World War II because during the war, soldiers needed to upgrade their uniform. This is to enable them to adapt to the battlefield where the deconstruction happened and courses of history have changed.

Answer:

150 Newtons

Explanation: