Answer: 7
Explanation:
The pH of water, a neutral substance, is 7. Human tears are a saline composed mostly of water. Therefore, it stands to reason that a tear-free shampoo would have a similar pH close to 7.
Answer:
the pH level would be 7
Explanation:
Radar consists of electromagnetic waves. A warplane is rendered invisible to enemy radar by applying an antireflective polymer coating. If radar waves have a frequency of 10 GHz (Giga = 1E9), and the index of refraction of the polymer for these waves is 1.50, what is the minimum thickness of the antireflective coating? (c = 3E8 m/s. The index of refraction of air is ~1, and that of the fuselage is larger than for the polymer coating)
Answer:
d = 0.015m
Explanation:
To find the thickness of the antireflective coating you take into account that waves must reflect and interfere destructively between them. A wave travels twice the thickness d of the coating, and for the destructive interference it is necessary that the reflected wave is (m+1/2) factor of the incident wave. Thus, you have:
[tex]2d=(m+\frac{1}{2})\lambda_n[/tex]
d: thickness of the coating
m: order of the interference (m=1 for the minimum thickness)
λn: wavelength of light inside the coating
You first calculate the wavelength of the wave:
[tex]\lambda=\frac{c}{f}=\frac{3*10^8m/s}{10*10^9Hz}=0.03m[/tex]
[tex]\lambda_{coating}=\lambda_n=\frac{n_{air}}{n_{coating}}\lambda_{air}\\\\\lambda_n=\frac{1}{1.50}(0.03m)=0.06m[/tex]
Then, you replace the values of m and λn in order to calculate d:
[tex]d=\frac{1}{2}(m+\frac{1}{2})\lambda_n[/tex]
[tex]d=\frac{1}{2}(0+\frac{1}{2})(0.06m)=0.015m=1.5cm[/tex]
hence, the thickness of the antireflective coating must be 0.015m
Which statement about velocity is true?
Answer:
Velocity has both speed and direction. Speed is constant. ... Speed is measured over time.
Explanation:
What is the definition of work in Physics?
Answer:
the mental and physical activities carried out by using energy are generally termed as work
A box is pulled to the right with a force of 65 n at an angle of 58 degrees to the horizontal the surface of frictional is the Freebody diagram shown what is the net force of the X direction
Answer:
The force acting in x direction is 34.44 N
Explanation:
We have,
Force acting on the box is 65 N at an angle of 58 degrees to the horizontal the surface of frictional.
It is required to find the net force in x- direction.
The net force acting in the x- direction is given by :
[tex]F_x=F\cos\theta\\\\F_x=65\times \cos(58)\\\\F_x=34.44\ N[/tex]
So, the force acting in x direction is 34.44 N.
If the speed and mass of an object are doubled, which of the following is true?
A) The momentum of the object is doubled
B) The kinetic energy of the object is doubled
C) The momentum of the object is quadrupled
D) The kinetic energy of the object is multiplied by 8
E) The momentum and the kinetic energy of the object are quadrupled
Answer:
A is true
Explanation:
Other all are wrong I guess
Answer: The Answer is A
Explanation:
I'm not sure but
P = Momentum
P = Mass x Velocity
P = (M XV)^2
P^2
Zona onde não incide luz visível devido à interposição de um objeto opaco.
Answer:
can you please translate to english?
Explanation:
The chart shows the power ratings of 3 clothes dryers and the time needed to dry a load of 10 towels.
power/time
x/4,370/25
y/4,420/22
z/4,150/26
What is the difference in energy used between the dryer that uses the greatest amount of energy and the dryer that uses the least amount?
Answer:
12010
Explanation:
Given:
power time
4,370 25
4,420 22
4,150 26
To find: difference in energy used between the dryer that uses the greatest amount of energy and the dryer that uses the least amount
Solution:
Energy = power × time
For clothes dryer x:
energy = 4370 × 25 = 109250
For clothes dryer y:
energy = 4420 × 22 = 97240
For clothes dryer z:
energy = 4150 × 26 = 107900
Dryer x uses the greatest amount of energy and dryer y uses the least amount of energy.
Difference in energy used between the dryer that uses the greatest amount of energy and the dryer that uses the least amount = 109250 - 97240 = 12010
Answer:
.20 kWh
Explanation:
its right on edge
What is work?
A. Force times an object's displacement
OB. The distance an object moves over time
C. The time it takes an object to move a certain distance
O D. The force that distance makes
SUBMIT
How the like and unlike poles of magnets interact
Answer:
like repel unlike attract
Explanation:
mmwwwwwww
Atividade 4 - Num chuveiro ligado nas posições verão e inverno, com as seguintes características: 220V – 2200W/4400W. Calcule a corrente elétrica que circula na potência menor (verão) e maior (inverno), com a mesma tensão. Dica: isole a corrente elétrica na expressão P= i x U
Explanation:
The characteristics for a shower connected in summer and winter positions is 220 V - 2200 W / 4400 W.
It means lowest power is 2200 W and highest power is 4400 W
For lowest power,
[tex]P=VI[/tex]
I = electric current for summer
[tex]I=\dfrac{P}{V}\\\\I=\dfrac{2200}{220}\\\\I=10\ A[/tex]
For highest power,
[tex]P'=VI'[/tex]
I' = electric current for winters
[tex]I'=\dfrac{P}{V}\\\\I'=\dfrac{4400}{220}\\\\I'=20\ A[/tex]
Hence, for lowest power, current is 10 A ad for highest power, current is 20 A.
What is food insecurity?
the state of being without reliable access to a sufficient quantity of affordable, nutritious food.
the state of being without food for at least five days
the state of being without food until mom or dad goes grocery shopping
the state of not cooking your own food to feed yourself
Answer:
The state of being without reliablr access to a sufficient quantity of affordable, nutritious food
WILL BE MARKED BRAINLIEST
IF CORRECT
In what ways are electromagnetic waves differed from mechanical waves?
A. Electromagnetic waves can only travel through matter.
B. Electromagnetic waves transfer matter through empty space.
C. Electromagnetic waves are longitudinal waves
D. Electromagnetic waves can travel through empty space
Answer:
C. Electromagnetic waves are longitudinal waves
Explanation:
Answer:
the answer is c
Explanation:
Is weightlifting an example of newton's 3rd law of motion? if so explain.
Describe the relationship between a moving object's mass and its kinetic energy.
Answer:
[tex]E=\dfrac{1}{2}mv^2[/tex]
Explanation:
If m is the mass of the object and v is the velocity of the object. The kinetic energy is due to the motion of an object. It is given by the relation as follows :
[tex]E=\dfrac{1}{2}mv^2[/tex]
The above formula is used to find the kinetic energy of an object.
Sonar question: A person's yells into a deep well, sending a sound wave that travels at a speed of 50 m/s. The echo is heard in 6 seconds.
How deep is the well? Remember, speed distance/time
When observed from Earth, the wavelengths of light emitted by a star are shifted toward the red end of the
electromagnetic spectrum. Why does this redshift occur?
Answer: The redshift occurs because the starts are moving away from the earth.
Explanation:
Every object emits wavelength from its body. When it comes to universe there are some visible light emitted by the stars and other objects in galaxy.
If a star is moving towards the sun then it emits a shorter wavelength compared to the source which is at rest. This is blue in color called as blue shift.
But when it comes to stars they move away from the earth and hence emits longer wavelength called as red shift.
As the object it at rest it more towards the blue side and when the objects starts moving it starts moving towards the red side in the visible spectrum.
So, when the starts moves away from the earth it forms a Redshift.
When observed from Earth, the wavelengths of light emitted by a star are shifted toward the red end of the electromagnetic spectrum because: the star is moving away from planet Earth.
A star is a giant astronomical or celestial object that contains a luminous sphere of plasma and bounded together by its own gravitational force.
A redshift can be defined as a displacement (shift) of the spectral lines of celestial or astronomical objects toward longer wavelengths (the red end of an electromagnetic spectrum), as a result of the Doppler effect.
Hence, a redshift is considered to be a subtle change in the color of visible electromagnetic radiation from stars (starlight), as observed from planet Earth.
In conclusion, a redshift occur when observing a star from planet Earth because the star is moving away from planet Earth.
Read more: https://brainly.com/question/17934476
Which type of wave is more dangerous for humans? Microwaves or x-rays?
Answer:
x-rays
Explanation:
SOMEONE HELP W THESE QUESTIONS PLEASEEE
3m/s²
5m/s²
I hope it helps
What is Newton's Law of Conservation of Momentum?
Answer: The law of conservation of linear momentum helps to understand the behavior of a Newton's cradle In a closed system. This law is nothing more than action and reaction.it can be used to predict the resulting direction and speed of motion of objects after they collide.
Explanation: Just as an example, when you play pool/8ball, the white play exerts force on the other balls causing them to break away.
hope this helps.
What are greenhouse gasses? How does carbon dioxide enter the atmosphere? (Site 1)
Answer:
greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range
Explanation:
Animals and plants need to get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned.
Answer and explanation:
Greenhouse gases are carbon dioxide, water vapor, fluorinated gases, nitrous oxide, methane, and others. Carbon dioxide enters the atmosphere by respiration of plants, animals, and microbes. Plants also remove carbon dioxide during photosynthesis. The net result is that plants remove more carbon dioxide than they contribute. Microbes and fungi that decompose plants and animals also return the carbon to the atmosphere as carbon dioxide. These are all ways nature cycles carbon. Humans contribute carbon dioxide to the atmosphere when we burn wood, solid waste, and fossil fuels. When forests are burned to clear land, not only does the burning release carbon dioxide, but it eliminates trees that would otherwise be removing carbon dioxide by photosynthesis. Most of the human contribution is from burning fossil fuels in electrical power plants that burn coal or natural gas and in vehicles that run on petroleum products. Other industrial processes also contribute carbon dioxide to the atmosphere, but to a lesser extent.
A wave with a frequency of 30 Hz has a wavelength of 40.5 m. How fast is the wave traveling?
Answer:
Speed of wave = 1,215 m/s
Explanation:
Given:
Frequency of wave = 30 Hz
Wavelength = 40.5 m
Find:
Speed of wave = ?
Computation:
⇔ Speed of wave = Frequency of wave × Wavelength
⇔ Speed of wave = 30 Hz × 40.5 m
⇔ Speed of wave = 1,215 m/s
Therefore, speed of wave is 1,215 meter per second.
9. A sports car travels on a straight road at 22.0 km/h and increases its speed to 57.0 km/h in
5.0 s. Find the car's acceleration in m/s?.
Answer:
4.4 M/s
Explanation:
Why are experiments often performed in laboratories?
O A. They are better at representing the real world.
O B. There are fewer variables to control.
C. Scientists only want to know what happens in labs.
O D. It is harder to control variables in a laboratory.
Answer:
B
Explanation:
Laboratories are usually controlled: however, in public places, there are way too many factors that could change an experiment
Is a tomatoes a substance of a acid or a base
I think tomato is acid
Answer:
acid
Explanation:
tomatoes contain acids such as citric acid, ascorbic acid, abscisic acid etc.
this indicates that they are acidic
Question 8 of 10
2 Points
A scientist gives three trees of the same size and species different amounts
of water all summer. He measures how fast the trees grow. What is the
independent variable in this experiment?
A. The amount of water
B. The growth rate of the trees
C. The month the trees are measured
D. The size of the trees
SUBMIT
A. The amount of water. 50/50
What is the primary way that metamorphic rocks forms?
Answer:
where the rocks are exposed to really hot conditions and high pressure....these conditions are found deep where tectonic plates meet or deep inisde the earth past our core
hope this helps !!!!!
Answer:
high heat, high pressure, hot mineral-rich fluids or commonly a combination of these found deep in the Earth or where tectonic plates meet.
Explanation:
I hope this helps :3
What is carried by a wave?
Answer
Energy
Explanation
wave is a disturbance which travels through a medium carrying energy from one point to another without causing any permanent displacement in that medium. So energy is carried by a wave.
A wave travels an average distance of 6 meters in 3 seconds. What is the wave's velocity?
Answer:
2m/s
.................
What happens to momentum when two objects collide
Answer:
The sum of momenta of each object before and after collision is equal . Thus when they collide , their momentum will change but its sum will be sane as the sum of the momentum before collision
He discovered that electricity could be mae by moving a magnet inside a wire coil
Answer:
Michael Faraday
Explanation:
Electromagnetic Induction was first discovered way back in the 1830's by Micahel Faraday. Faraday noticed that when he moved a permanent magnet in and out of a coil or a single loop of wire it induced an ElectroMotive Force or emf, in other words a Voltage, and therefore a current was produced.