Complete question is;
The frequency and wavelength of EM waves can vary over a wide range of values. Scientists refer to the full range of frequencies that EM radiation can have as the electromagnetic spectrum. Electromagnetic waves are used extensively in modern wireless technology. Many devices are built to emit and/or receive EM waves at a very specific frequency, or within a narrow band of frequencies. Here are some examples followed by their frequencies of operation:
garage door openers: 40.0 MHz
standard cordless phones: 40.0 to 50.0 MHz
baby monitors: 49.0 MHz
FM radio stations: 88.0 to 108 MHz
cell phones: 800 to 900 MHz
Global Positioning System: 1227 to 1575 MHz
microwave ovens: 2450 MHz
wireless internet technology: 2.4 to 2.6 GHz
Which of the following statements correctly describe the various applications listed above? Check all that apply.
a.) All these technologies use radio waves, including low-frequency microwaves.
b.) All these technologies use radio waves, including high-frequency microwaves.
c.) All these technologies use a combination of infrared waves and high-frequency microwaves.
d.) Microwave ovens emit in the same frequency band as some wireless Internet devices.
e.) The radiation emitted by wireless Internet devices has the shortest wavelength of all the technologies listed above.
f.) All these technologies emit waves with a wavelength in the range of 0.10 to 10.0 m.
g.) All the technologies emit waves with a wavelength in the range of 0.01 to 10.0 km.
Answer:
B, D, E, F are the correct statements.
Explanation:
Looking at the options;
A) This is true because radio waves are electromagnetic radiation being used today in television, mobile phones, radios and other areas of communication technologies. And the examples given to us fall in the category of technologies that use radio waves.
B) microwaves usually have long wavelengths and low frequencies. However, sometimes they could have high frequencies usually more than radio waves. Thus, this option is correct.
C) This option is wrong because it's not all the listed technologies that use combination of infrared waves and high-frequency microwaves.
D) we are given the frequency of microwave ovens as 2450 MHz.
Converting to GHz gives; 2.45 GHz.
We are told that wireless internet technology has frequency between 2.4 to 2.6 GHz. Thus, microwave frequency falls in the same range as wireless internet technology and thus the statement is true.
E) we know that wavelength is inversely proportional to frequency. This means that the higher the frequency, the shorter the wavelength.
In the frequencies given to us, wireless internet technology have the highest frequency which means they have the shortest wavelength. The statement is true.
F) from the frequencies given to us, the smallest is garage door openers = 40.0 MHz = 40 × 10^(6) Hz while the biggest is 2.6 GHz = 2.6 × 10^(9) Hz
Formula for wavelength is;
Wavelength = speed of light/frequency
Speed of light = 3 × 10^(8) m/s
Thus;
Wavelength = (3 × 10^(8))/(40 × 10^(6))
Or wavelength = (3 × 10^(8))/(2.6 × 10^(9))
So,wavelength = 7.5 m or 0.12 m
This falls into the given range of 0.10 to 10.0 m.
Thus, the statement is true.
In the past, asteroids striking the earth have produced disastrous results. If we discovered an asteroid on a collision course with the earth, we could, in principle, deflect it and avoid an impact by focusing a laser on the surface. Intense surface heating from the laser could cause surface material to be ejected into space at high speed.
Required:
How would this deflect the asteroid?
Answer:
Explained below.
Explanation:
We are told that the surface material is ejected into space at a high speed. This means that it will have a likely high momentum as well.
Now, we can say that the total momentum is conserved because the entire asteroid system behaves like an isolated system.
Also, as the surface material is moving with the high momentum like we established earlier, it will cause the asteroid to move with a speed in an opposite direction which also means deflection in an opposite direction.
Answer:
Explained below.
Explanation:
The material ejected from the surface of the asteroid would have a significant momentum. Since the asteroid and all its material is an isolated system, the ejection would cause an oppositely directed change in momentum of the asteroid, according to the law of conservation of momentum.
The ejected material is analogous to gases expelled from a rocket, and the asteroid is analogous to a rocket.
What are the five classes of objects that orbit the sun?
Electricity is distributed from electrical substations to neighborhoods at 13000 V. This is a 60 Hz oscillating (AC) voltage. Neighborhood transformers, seen on utility poles, step this voltage down to the 120 V that is delivered to your house.
A. How many turns does the primary coil on the transformer have if the secondary coil has 120 turns?
Answer:
the number of turns in the primary coil is 13000
Explanation:
Given the data in the question;
V₁ = 13000 V
V₂ = 120 V
N₁ = ?
N₂ = 120 turns
the relation between the voltages and the number of turns in the primary and secondary coils can be expressed as;
V₁/V₂ = N₁/N₂
V₁N₂ = V₂N₁
N₁ = V₁N₂ / V₂
so we substitute
N₁ = (13000 V × 120 turns) / 120 V
N₁ = 1560000 V-turns / 120 V
N₁ = 13000 turns
Therefore, the number of turns in the primary coil is 13000
You are testing a new amusement park roller coaster with an empty car with a mass of 130 kg . One part of the track is a vertical loop with a radius of 12.0 m . At the bottom of the loop (point A) the car has a speed of 25.0 m/s and at the top of the loop (point B) it has speed of 8.00 m/s . Part A As the car rolls from point A to point B, how much work is done by friction
Answer:
work done by friction = 5889 J
Explanation:
We are given;
Mass of car; m = 130 kg
Speed at point A; v1 = 25 m/s
Speed at point B: v2 = 8 m/s
Since radius is 12 m
At point A, distance is; y1 = 12 m
At point B, distance is; y2 = -12 m
Now, formula for work done by all the forces is given by the equation;
Total work;
W_gravity + W_others = K2 - K1
Where W_others is work done by other forces which is equal to work done by friction
Where K2 - K1 is change in kinetic energy.
W_grav is also change in potential energy and is expressed as;
W_grav = mgy1 - mgy2
K2 - K1 = ½m(v1)² - ½m(v2)²
Thus;
mgy1 - mgy2 + W_others = ½m(v1)² - ½m(v2)²
Making W_others the subject;
W_others = ½m(v1)² - ½m(v2)² + mgy2 - mgy1
Plugging in the relevant values;
W_others = (½ × 130 × 25²) - (½ × 130 × 8²) + (130 × 9.8 × -12) - (130 × 9.8 × 12)
W_others = 5889 J
Recall that I earlier said W_others = work done by friction.
Thus, work done by friction = 5889 J
a)
What is the net force on the refrigerator shown to the right?
200 N
1,000 N
50 N
= Fg
1,000 N = F.
b) Calculate the mass of the refrigerator.
c) What is the refrigerator's acceleration?
Answer:
50N
Explanation:
is the opposing fotce
FIRST CORRECT ANSWER GETS BRAINLIEST!!!
Answer:
Light is being absorbed
Hope this helps!
Light is being absorbed
Scientists have concluded that the uppermost part of the mantle is partially-molten. Which observation helped them reach this conclusion?
Answer:
P and S waves slow down when they reach this layer. The asthenosphere, also known as the magma chamber, is the uppermost component of the mantle. This layer is partially molten and is a ductile zone in a tectonically poor state.
It's almost hard and seismic waves move through the asthenosphere at a slow rate. The fragile lithosphere and the uppermost portion of the asthenosphere are assumed to be rigid.
seismic waves travel more quickly through denser materials and therefore generally travel more quickly with the depth it moves more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid. Partially molten areas may slow down the P waves and attenuate or weaken S waves.
hope this helps...
S and P wave slow down and stop in the uppermost part of the mantle. - For this, scientists have concluded that the uppermost part of the mantle is partially-molten.
What is mantle?A planetary body's mantle is a layer that is surrounded by the crust on top and the core underneath. The largest and most substantial layer of a planetary body, mantles are often comprised of rock or ice. Planetary bodies that have undergone density differentiation typically have mantles. Mantles are found on all terrestrial planets (including Earth), many asteroids, and a few planetary moons.
Between the crust and the outer core, there is a silicate rock layer known as the Earth's mantle. Despite being mostly solid, it behaves like a viscous fluid over geological time. Oceanic crust is created by the partial melting of the mantle at mid-ocean ridges, and continental crust is created by the partial melting of the mantle at subduction zones.
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How many gallons of water does it take to produce the following:
a. Cheeseburger
b. Pound of butter
c. A pair of jeans
Answer:
a. 660 gallons
b.665 gallons
c. 1,800
3) Which of the following can affect the success of a start-up business?
A) the entrepreneur's ability to communicate
B) the entrepreneur's ability to resolve conflict
C) the entrepreneur's ability to work with his employees
D) all of the above
Answer:
all of the above.
Explanation:
all of these qualities are crucial in order to have a successful business.
Easy question I’ll give extra points. Help
Answer:
the answer is A
I wish you a good day!
Answer:
THe answer is graph 2 as it represents the puck going in a linear motion
Explanation:
A 64.0 cm long cord is vibrating in such a manner that it forms a standing wave with two antinodes. (The cord is fixed at both ends.) Which harmonic does this wave represent
Answer:
the wave represents the second harmonic.
Explanation:
Given;
length of the cord, L = 64 cm
The first harmonic of a cord fixed at both ends is given as;
[tex]f_o = \frac{V}{2L}[/tex]
The wavelength of a standing wave with two antinodes is calculated as follows;
L = N---> A -----> N + N ----> A -----> N
Where;
N is node
A is antinode
L = N---> A -----> N + N ----> A -----> N = λ/2 + λ/2
L = λ
The harmonic is calculated as;
[tex]f = \frac{V}{\lambda} \\\\f = \frac{V}{L} = 2(\frac{V}{2L} ) = 2(f_o) = 2^{nd} \ harmonic[/tex]
Therefore, the wave represents the second harmonic.
L = λ
A 4-foot spring measures 8 feet long after a mass weighing 8 pounds is attached to it. The medium through which the mass moves offers a damping force numerically equal to 2 times the instantaneous velocity. Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 7 ft/s. (Use g
Correct question is;
A 4-foot spring measures 8 feet long after a mass weighing 8 pounds is attached to it. The medium through which the mass moves offers a damping force numerically equal to √2 times the instantaneous velocity. Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 7 ft/s. (Use g = 32 ft/s²)
Answer:
x(t) = 7te^(-2t√2)
Explanation:
We are given;
Weight; W = 8 lbs
mass; m = W/g
g = 32 ft/s²
Thus;
m = 8/32
m = ¼ slugs
From Newton's second law we can write the equation as;
m(d²x/dt²) = -kx - β(dx/dt)
Rearranging this, we have;
(d²x/dt²) + (β/m)(dx/dt) + (k/m)x = 0
Where;
β is damping constant = √2
k is spring constant = W/s
Where s = 8ft - 4ft = 4ft
k = 8/4
k = 2
Thus,we now have;
(d²x/dt²) + (√2/(¼))(dx/dt) + (2/(¼))x = 0
>> (d²x/dt²) + (4√2)dx/dt + 8x = 0
The auxiliary equation of this is;
m² + (4√2)m + 8 = 0
Using quadratic formula, we have;
m1 = m2 = -2√2
The general solution will be gotten from;
x_t = c1•e^(mt) + c2•t•e^(mt)
Plugging in the relevant values gives;
x_t = c1•e^(mt) + c2•t•e^(mt)
At initial condition of t = 0, x_t = 0 and thus; c1 = 0
Also at initial condition of t = 0, x'(0) = 7 and thus;
Since c1 = 0, then c2 = 7
Thus,equation of motion is;
x(t) = 7te^(-2t√2)
A car accelerates from rest to 35m/s in a distance of 88 m. What was its acceleration in m/s2, assumed constant?
Answer:
6.96ms/2 or 7ms/2
Explanation:
v2=u2 +2as second equation of motion
u=o
v=35
S=88
a=?
35^2=0^2 +2xax88
=1225 =0+176a
1225=176a
1224/176=6.96ms/2 or 7ms/2
The potential energy of a mass-spring system when the spring is fully compressed and the mass is at rest is 200 J. After releasing the mass, assuming there is no dissipative force, the system will oscillate. At a point during the oscillation the potential energy of the system is 50 J. What is the kinetic energy of the mass at that point
Answer:
150 J
Explanation:
If there is not any dissipative force in the system, the mass and the spring will oscillate eternally., but of course, we assume this is a theoretical situation. The conservation of energy in a system implies that the sum of the potential energy plus kinetic energy remains constant, therefore if in the initial point the mass has 200 J (potential energy) and is at rest ( kinetic energy = 0) the overall energy at the beginning is 200 J. At any point of the oscillation if the potential energy is 50 J the kinetic energy must be 150 J.
Why do herbivores of the Serengeti migrate year after year
Answer:
The main reason is that very young calves are more noticeable to predators when mixed with older calves from the previous year
Explanation:
They are forced to migrate by carnivores that hunt them.
What is the approximate surface temperature of the 'White Dwarfs'?.
2,500-5,000 K
5,000-10,000
10,000-15,000 K
15,000 K-35,000 K
Answer:
5,000-10,000 K
Explanation:
make me your brainlist pls
Please help me with this question. Every help is appreciated.
Answer:
Change in KE = +1.96×10^4 J while the change in ME = 0 J
Raven knows that ammonia will react with vinegar when they are both dissolved in water. She's concerned the reaction will go too quickly. How can she slow down the reaction?
Question 13 options:
Increase the concentration of dissolved substances
Decrease the concentration of dissolved substances
Add a catalyst
There's nothing she can do to change the rate of reaction.
Question 14 (2 points)
Which of the following is a solution?
Question 14 options:
Popcorn
A salad
Pure water
Salt dissolved in water
Question 15 (2 points)
The picture shows two solutions of salt water. Which solution is more concentrated (has a higher concentration)?
Question 15 options:
The first solution is more concentrated
The second solution is more concentrated
The solutions have the same concentration.
Question 16 (2 points)
What must occur for particles to react?
Question 16 options:
They must collide
They must photosynthesize
They must condense
They must melt
Question 17 (3 points)
In your opinion, what the most important OR interesting thing from this unit? If you didn't find anything interesting, please write one thing that you learned.
Write a full sentence, please.
Question 17 options:
A solution is a homogeneous mixture, which may be liquid, gas or solid, formed by dissolving one or more substances.
According to this question, a salt dissolved in water is an example of solution because it involves a solute and a solvent.
The rate of a chemical reaction can be decreased by reducing the concentration of the reactants so as not to provoke a reaction.
In a chemical reaction, the particles of the reactants must collide to initiate the reaction.
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When jeremiah stands in a swimming pool and looks at hid feet, his legs appear to be bent. Which is the term for this phenomenon?
A. Diffraction
B. Dispersion
C. Reflection
D. Refraction
What is respiration?
Answer:
taking in oxygen and giving out carbon dioxide is called respiration
Answer:
i think that respiratiln is when you breqth
This photo shows a beam of light entering and exiting a piece of glass.
What happens when the light enters the glass?
A. The light is absorbed.
B. The light is reflected.
C. The light is scattered.
D. The light is refracted.
Answer:
D. The Light Is Refracted
Explanation:
<3
The kinetic energy and the potential energy of the cannonball is constantly ________ as it travels through the air.
A. Changing
B. Increasing
C. Constant
D. Decreasing
Answer:
C. Constant
Explanation:
The total energy of the cannonball remains constant as it travels through the air.
Answer:
Explanation:
hi my name is Ava
Need a 5 paragraph essay in the eartsh layers and how they function/ benefit the earth!
There is more to the Earth than what we can see on the surface. In fact, if you were able to hold the Earth in your hand and slice it in half, you'd see that it has multiple layers. But of course, the interior of our world continues to hold some mysteries for us. Even as we intrepidly explore other worlds and deploy satellites into orbit, the inner recesses of our planet remains off limit from us.
However, advances in seismology have allowed us to learn a great deal about the Earth and the many layers that make it up. Each layer has its own properties, composition, and characteristics that affects many of the key processes of our planet. They are, in order from the exterior to the interior – the crust, the mantle, the outer core, and the inner core. Let's take a look at them and see what they have going on.
Like all terrestrial planets, the Earth's interior is differentiated. This means that its internal structure consists of layers, arranged like the skin of an onion. Peel back one, and you find another, distinguished from the last by its chemical and geological properties, as well as vast differences in temperature and pressure.
Explanation:
Water can form large dewdrops in nature how would droplets made of isopropyl alcohol instead of water be different
Answer:
isopropyl alcohol would form smaller droplets, because it has lower surface tension than water has
Explanation:
Ap3x
The droplets made of isopropyl alcohol instead of water be smaller due to surface tension.
What is droplets?The single drop of a liquid in the form of sphere is called droplet.
Water can form large dewdrops in nature. Isopropyl alcohol would form smaller droplets, because it has lower surface tension than water.
Surface tension is the property of the liquid to acquire minimum surface area.
Thus, droplets made of isopropyl alcohol instead of water be smaller.
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if matter cannot be created nor destroyed where did the matter in the univerce com from ???????
BIG BRAIN
i have no idea
I don't even know how we are here
What voltage would be measured across the 15 ohm resistor?
A)
2.5 volts
B)
5.0 volts
C)
7.5 volts
D)
10 volts
Answer:
7.5 volts
Explanation:
I did it on USA Testprep
A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each 15 cm long. A 0.7 T uniform magnetic field is parallel to the hypotenuse. The total magnetic force on the two equal sides has a magnitude of:Group of answer choices0.30 N0 N0.51 N0.41 N
Answer:
the total magnetic force on the 2 sides of the wire is 0.30 N
Option a) 0.30 N is the correct answer
Explanation:
Given the data in the question;
both the sides of the right angled triangle is the same and the magnetic is in the plane of the triangle and is perpendicular to the hypotenuse.
hence, angle between the magnetic field and both the sides of the triangle is 45 degrees.
∅ = 45°
I = 2.0 A
L = 15 cm = 0.15 m
B = 0.7 T
Total magnetic force on the 2 sides of the wire will be;
F = 2BILsin∅
we substitute
F = 2 × 0.7 × 2.0 × 0.15 × sin(45°)
F = 0.42 × 0.70710678
F = 0.2970 ≈ 0.30 N
Therefore, the total magnetic force on the 2 sides of the wire is 0.30 N
Option a) 0.30 N is the correct answer
20. How does a paraxylene crystallizer operate?
In the CrystPX Technology process, suspension crystallization of paraxylene (PX) in the xylene isomer mixture is used to produce paraxylene crystals. At the back end of the process, high paraxylene recovery is obtained by operating the crystallizers at colder temperatures.
Paraxylene crystals are created using the CrystPX Technology by suspending paraxylene (PX) in a mixture of xylene isomers. High paraxylene recovery is achieved at the end of the process by running the crystallizers at lower temperatures.
What does a paraxylene crystallizer operate?The paraxylene technology from BP, a novel method using single stage crystallization for paraxylene (pX) recovery, is licensed exclusively to Lummus Technology for use around the world.
This cutting-edge architecture makes the Lummus Technology/BP pX crystallization technology the most energy-efficient paraxylene recovery process, together with excellent feed impurity tolerance and low total unit fuel consumption.
The Lummus Technology/BP paraxylene process has a high degree of dependability, is inexpensive, and can take a variety of feed compositions.
Therefore, With the aid of isomerization over a non-noble metal catalyst, the yield of xylene is improved even further. Optimized fractionation lowers reboiler duty, resulting in less energy use and emissions.
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Select the correct answer.
F₁ = 70 N
F₂ = 15 N
8
F₁
W = 80 N
Use this free body diagram to help you find the magnitude of the force F₁ needed to keep this block in static equilibrium.
Explanation:
F1 will have to have 65 N vertical up force to balance the net 65 N down on the body AND it will have to have 70 N horizontal to the right to balance the 70 N force that is acting to the left
Magnitude = sqrt ( 65^2 + 70^2) = 95.5 N
A man walks 30 m to the west, then 5 m to the east in 45 seconds.
What is his average speed?