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Related Questions
How many free electrons are there in 2.55 cm^ ^ 3 of pure Silicon Note N = Vp and rho = 1.54 free electrons / cm ^3
A: 3.93 x 10^20 free electrons
B: 6.32 x 10^20 free electrons
C: 3.93 x 10^22 free electrons
D: 6.32 x 10^2× free electrons
Answers
Answer:
C: 3.93 x 10^22 free electrons
Explanation:
The no. of free electrons can be found out using the following formula:
[tex]N = V\rho\\[/tex]
where,
N = No. of free electrons = ?
V = Volume = 2.55 cm³
ρ = density of electrons = 1.54 x 10²² free electrons/cm³
Therefore, using these values in the equation, we get:
[tex]N = (2.55\ cm^3)(1.54\ x\ 10^{22}\ free\ electrons/cm^3)\\[/tex]
N = 3.93 x 10²² free electrons
Therefore, the correct option is:
C: 3.93 x 10^22 free electrons
Which one of the following statements is true: The reactive power is the power dissipated in the form of heat by the network. The reactive power is the power delivered to a load without considering the effects of the power-factor angle of the load. The apparent power is the power delivered to a load without considering the effects of the power-factor angle of the load. The real power is the power associated with reactive elements that provides a measure of the energy associated with setting up the magnetic and electric fields.
Answers
Answer:
The apparent power is the power delivered to a load without considering the effects of the power-factor angle of the load
Explanation:
If I and V are the current and voltage across the load, the apparent power, = IV
Since,
apparent power = active power + reactive power
active power = IVcosФ
reactive power = IVsinФ
So, IV = IVcosФ + IVsinФ
where I = current, V = voltage and Ф = power factor angle.
We see that the apparent power is the product of the current, I and the Voltage, V without considering the power factor angle of the load.
So, the apparent power is the power delivered to a load without considering the effects of the power-factor angle of the load.
A bus contains a 1500 kg flywheel (a disk that has a 0.600 m radius) and has a total mass of 10,000 kg.
(a) Calculate the angular velocity the flywheel must have to contain enough energy to take the bus from rest to a speed of 20.0 m/s, assuming 90.0% of the rotational kinetic energy can be transformed into translational energy.
(b) How high a hill can the bus climb with this stored energy and still have a speed of 3.00 m/s at the top of the hill? Explicitly show how you follow the steps in the Problem-Solving Strategy for Rotational Energy.
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Answer:
Explanation:
moment of inertia of flywheel = 1/2 m R²
= .5 x 1500 x .6²
= 270 kg m²
If required angular velocity be ω
rotational kinetic energy = 1/2 I ω²
= .5 x 270 x ω² = 135 ω²
kinetic energy of bus when its velocity is 20 m/s
= 1/2 x 10000 x 20²
= 2000000 J
Given 90 % of rotational kinetic energy is converted into bus's kinetic energy
135 ω² x 0.9 = 2000000 J
ω²=16461
ω = 128.3 radian /s
b )
Let the height required be h .
Total energy of bus at the top of hill = mgh + 1/2 m v²
m ( gh + .5 v²)
= 10000 ( 9.8h + .5 x 3²)
From conservation of mechanical energy theorem
10000 ( 9.8h + .5 x 3²) = 2000000
9.8h + .5 x 3² = 200
9.8h = 195.5
h = 19.95 m .
Matter cant be created or destroyed
true
false
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Answer: True
no matter can be created nor destroyed in any process. if something is burned, made in a compound or anything like that all matter is still the same amount from beginning to end.
Explanation:
¿Qué proporción deberían guardar los platos de una prensa hidráulica para que, aplicando 40N de fuerza en el plato menor, podamos levantar un objeto de 40Kg en el plato mayor?
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Answer:
El área de la placa más grande es aproximadamente 9,81 veces el tamaño del área de la placa más pequeña
Explanation:
Los parámetros dados son;
La fuerza aplicada sobre la placa más pequeña, F = 40 N
El culo del objeto levantado en la placa más grande, m = 40 kg
El peso del objeto, W = 40 kg × 9,81 m / s² = 392,4 N
Tenemos la presión en el plato pequeño = La presión en el plato más grande
Por lo tanto;
F / A₁ = W / A₂
Dónde;
A₁ = El área del plato pequeño
A₂ = El área de la placa más grande
Por lo tanto, obtenemos;
40 N / (A₁) = 392,4 N / (A₂)
A₂ / A₁ = 392,4 N / (40 N) = 9,81
∴ A₂ = A₁ × 9,81
El área de la placa más grande, A₂ = 9,81 (9,81 m / s² ≈ g) multiplicado por el área de la placa más pequeña A₁.
What effect would constriction of the blood vessels have on the body?
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Answer:
When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. this makes the skin turn paler because the blood reaches the surface, reducing the radiation of heat. hope this helps
Which statement describes the energy transformation that occurs when a person eats a sandwich to gain energy for a long hike?
A. Electrical energy stored in the molecules of the sandwich is transformed into chemical energy.
B. Kinetic energy stored in the bonds of the molecules of the sandwich is transformed into chemical energy.
C. Thermal energy stored in the molecules of the sandwich is transformed into kinetic energy.
D. Chemical energy stored in the bonds of the molecules of the sandwich is transformed into kinetic energy.
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D. Chemical energy stored in the bonds of the molecules of the sandwich is transformed into kinetic energy. This statement describes the energy transformation that occurs when a person eats a sandwich to gain energy for a long hike
What is Law of energy conservation ?
Law of energy conservation states that energy can neither be created nor be destroyed and can only transform from one form to other form.
From Law of energy conservation we can say that Digestion starts from that very point when we put food in our mouth so the moment you eat the sandwich, it starts getting digested and when it reaches the stomach ,your body converts its chemical energy into the movement of your muscles.
hence , correct option is :
D. Chemical energy stored in the bonds of the molecules of the sandwich is transformed into kinetic energy.
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A food web is shown below. Hawk Fox Snake Mouse Frog Grasshopper Beetle Fungus Grass Which organisms could be both predators and prey depending on the relationship represented on the food web? A Hawk and fox B Grasshopper and beetle C Snake, frog, and mouse D Fungus and grass
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Answer:
A
A fox and hawk can be both a predator and prey
A 12 kg ball is rolling with a velocity of 10 m/s. How much kinetic energy does the ball have?
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Answer:
600 J
Explanation:
KE = 1/2 mv^2
Which best describes the type of lens that would help someone with one of these eye conditions? Concave lenses would help someone who is nearsighted because the lenses make objects look smaller and closer. Concave lenses would help someone who is farsighted because the lenses make objects look smaller and closer. Convex lenses would help someone who is nearsighted because the lenses can make objects look smaller and closer. Convex lenses would help someone who is nearsighted because the lenses can make objects look larger and farther away.
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Answer:
The answer is "Option a".
Explanation:
The concave lenses are there for narrow-sighted people, convex for the far people. In eyewear, curved lenses are used to rectify visibility. Since in nearsighted individuals the width between the eye lens as well as the retina is larger than should be, these readers can't clearly distinguish distant things.
Answer:
The correct answer is - Concave lenses would help someone who is nearsighted because the lenses make objects look smaller and closer.
Explanation:
Concave lenses are related to the condition of nearsightedness whereas convex lens is related to the farsightedness. Nearsightedness is the condition where a person can see closer objects clearly but the objects at a farther distance can not see properly.
Concave lenses make objects look smaller and closer as it makes the image farther than it is actually. It forms a virtual image as it is a diverging lens.
A(n) _________ is an object that is thrown.
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Answer:
projectile
Explanation:
Answer:
the answer is projectile
Explanation:
this is because like take a nerf gun for example when u fire it PROJECTS the dart from the gun. may i be marked brainliest?
Which statement best describes Cleo's mistake? Light travels through air and water in angled, scattered paths. Light does not change direction when it moves from air into water. Light slows down when it moves from air into water. Light bends away from the normal when it moves from air into water.
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The question (obtained from the internet);
Cleo stated that light travels through air in straight paths, and when it moves from air to water, light changes direction, speeds up, and bends towards the normal
Answer:
The statement that best describes Cleo's mistake is;
Light slows down when it moves from air into water
Explanation:
The question;
Cleo stated that light travels through air in straight paths, and when it moves from air to water, light changes direction, speeds up, and bends towards the normal
The speed of light in water = 225,000 km/s
The speed of light in air = 299,702,547 m/s
The speed of light in vacuum = 299,792,458 m/s
Therefore, light slows down when it moves from a less dense medium to a denser medium
Light moves closer (bends) towards the normal when it moves from air into water. Light therefore, changes direction, and light moves in straight path which is known as rectilinear motion
Therefore, the statement that describes Cleo's mistake is that light actually slows down when it moves from air into water.
Which of the following wave on the electromagnetic spectrum has more energy? Ultraviolet or x-rays?
Answers
Answer: ultraviolet
Explanation:
A child drops a bouncy ball. Each time it bounces, it reaches a lower height until it eventually
stops. Describe the energy transfers and explain why the ball lowered in height
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Answer:
the ball's was lowered because of the gravitational force and because of the friction force's
can we detect em waves with our eyes?
tru or false
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Explanation:
TRUE
Your eyes detect electromagnetic waves that are roughly the size of a virus. Your brain interprets the various energies of visible light as different colors, ranging from red to violet. ... On the other end of the spectrum are gamma rays, with wavelengths billions of times smaller than those of visible light
Hope this helps
Please help, I’m being timed! I will give brainliest!!!!!!!
Answers
Answer:
The Answer is gonna be A. It will speed up
Explanation :if it has the same velocity it will only change if the weight is less
This is the Answer
I hope I helped
I hope you are having a great day :3:3:3:3:3:3
Answer:
B
Explanation:
Why would it speed up if it is the same velocity??
It would stay at teh same speed. It would only increase if it weighed less.
Using the information provided in the table, which statement BEST describes the object's motion?
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Answer:
the velocity is decreasing therefore acceleration is negative
How is it possible a plant can sustain itself for 70 years locked inside a jar ?
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Answer:
If you are talking about the experiment in which mouse and plants are kept in a closed glass jar in sunlight so in that case, they both survive because the CO2 released by the respiration of mouse is being utilized by the plants and fixed ( phosynthesis) and O2 is released as by product, which is taken by the mouse for respiration.
A polythene rod may be charged by rubbing it with a cloth while being held in the hand but a metal rod cannot be charged in a similar way. Explain why
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Answer:
Explanation:
This is because polythene rod is an insulator , therefore when it is rubbed with a cloth , electrons move easily therefore making it charged but
Metal rod is a conductor, it conduct heat . Therefore, their atoms have electrons that is constantly in motion. Therefore rubbing it with a cloth will make any difference in making it charged because it have very huge number of stable electrons which will not allow more electrons to move through them.
An object's velocity/speed increases, multiplied by a factor of 7. What factor would its Kinetic Energy increase by?
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Answer:
k.E= 49 ms^-2
Explanation:
k.E= 1/2 mv^2
From that formula of k.E
K.E is directly proportional to the ( velocity)^2
K.E directly proportional to (7)^2
so that k.E increase by 49
Mainly need help with part A. No links, thanks!
Answers
Answer:
R = 4Ω
Explanation:
If we have two resistors with resistances R1 and R2 in series the total resistance is R = R1 + R2
If the resistances are in parallel, the total resistance is given by:
1/R = 1/R1 + 1/R2.
First, we have a resistor with R1 = 1.5Ω
This resistor is connected in series with a parallel part (let's find the resistance of this parallel part), in one branch we have two resistors in series with resistances:
R2 = 8Ω and R3 = 4Ω
Because these are in series, the resistance of that branch is:
R = 8Ω + 4Ω = 12Ω
In the other branch, we have a single resistor of R4 = 4Ω
The resistance of the parallel part is:
1/R = 1/12Ω + 1/4Ω = 1/12Ω + 3/12Ω = 4/12Ω = 1/3Ω
1/R = 1/3Ω
R = 3Ω
Then we have a resistor (the first one, R1 = 1.5Ω) in series with a resistor of 3Ω.
Then the total resistance is:
R = 1Ω + 3Ω = 4Ω
The shortening of a transmitted signal's wavelength and/or an increase in its frequency, which indicates that the object is
moving toward the observer, is called the
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Answer: The Doppler effect occurs when a source of a wave is moving relative to an observer (or the observer is moving relative to the source). In this case, the apparent frequency of the sound, as heard/seen by the observer, is shifted with respect to the original frequency of the wave.
More specifically, the relationship between the apparent frequency, f', and the original frequency, f, is given by:
where:
is the velocity of the wave
is the velocity of the observer relative to the source, and it is positive if the observer is moving towards the source, and negative if the observer is moving away from the source
is the velocity of the source relative to the observer, and it is positive if the source is moving away from the observer, and negative if the source is moving towards the observer
The doppler effect occurs in many daily-life situations: for instance, when an ambulance approaches you, you hear an increase in the apparent frequency of the siren due to the Doppler effect. Another example is the movements of distant galaxies from us: when they move away from us, the apparent frequency of the light they emit decreases, so their wavelengths appear to increase towards the red color (red-shift); on the contrary, when they are moving towards us, the apparent frequency seems to increase, so the wavelength seems to decrease towards the blue color (blue-shift).
Explanation:
What is the Average Depth of the ocean?
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Answer:
The average depth of the ocean is about 12,100 feet.
Explanation:
A DVD spins with a period of 0.016 seconds. With what frequency is the DVD
spinning?
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Answer:
It spins on the side where it looks shiny.
Explanation:
Answer:
9120-25600 RPM mate
Explanation:
I know your thinking it's crazy because of the other answer. but don't worry i looked it up for ya.
A step down transformer has a primary coil consisting of 700 tons and a secondary coil consisting of 300 times. What is the potential difference in the second circuit, if the primary coil is supplied with an effective AC potential difference of 110 V?
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Answer is 47.14 v
by the relation
[tex]\frac{V out}{V in } = \frac{N secondary}{N primary }[/tex]
Tammy is a forensic investigator examining a body at a crime scene. She notes that the body is stiff but still flexible. What does she know about the time of death?
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Answer:
It happened less than 8 hours ago.
Explanation:
Over the first eight hours, the body begins to stiffen but is still flexible.
List five objects in your daily life that produce sounds with a high pitch and five that produce sounds with a low pitch.
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Answer:
Explanation:
High pitch:
-birds chirping
-nails on a chalkboard
-flies buzzing
-children squealing
-whistle
Low pitch:
-thunder
-dogs barking
- earthquakes
- bass drum,
-cannon shot,
5 example of high pitch sound
baby crying , whistle , school bell , fire alarm , chirping of birds
5 example of low pitch sound
thunder , drum , earthquake , generator , animal roar
What is a pitch ?
It is the effect or sensation produce in brain due to sound of some particular frequency
5 example of high pitch sound
baby crying , whistle , school bell , fire alarm , chirping of birds
5 example of low pitch sound
thunder , drum , earthquake , generator , animal roar
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A) write the name of any two instrument based on atmoshpheric pressure.
B)Which chemical is used to increase the setting period of cement?
C)What are the near point and far point of normal eye?
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Answer:
Explanation:(a)Mercury Barometer and Aneroid Barometer
(b)Gypsum
(c)Near point of human eye is 25 cm and the far point is infinity.
Which statement about the minerals plagioclase feldspar, gypsum, biotite mica, and talc can best be inferred from the chart? (1) These minerals have the same
chemical and physical properties. (2) These minerals have different chemical properties, but they have similar physical properties. (3) These minerals have different physical and chemical properties, but they have identical uses. (4) The physical and chemical properties of these minerals determine how humans use them.
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Answer:
(4) The physical and chemical properties of these minerals determine how humans use them.
Explanation:
All the materials and the metals found on earth shows certain characteristics naturally or in their physical state. These physical characteristics can be their look, their structure, their color, strength, melting point, boiling point, density, etc.
And chemical properties of the metals are defined as those characteristics or features of the metals that it exhibits when these metals reacts chemically.
The physical properties as well as the chemical properties distinguishes each metal from each other. These properties determines how people use these metals in their life.
Which beach balls have potential energy and not kinetic energy?
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Answer:
Beach ball 4
Explanation:
it is because, Potential Energy = M G H
P(e) directly proportional to H.
if H increase then P energy also increases