8 points)Antireflection coating can be used on the eyeglasses to reduce the reflection of light: a) A 100nm thick coating is applied to the lens. What must be the coating’s index of refraction to be most effective at 500nm? (Assume the coating index of refraction is less than that of the lens). b) If the index of refraction of the coating is 1.20, find the necessary thickness of the coating at 500nm.
Answer:
- the coating’s index of refraction is 1.25
- the required thickness is 104.1667 nm
Explanation:
Given the data in the question;
Thickness of coating t = 100 nm
wavelength λ = 500nm
we know that refractive index is;
t = λ/4n
make n, the subject of formula
t4n = λ
n = λ / 4t
we substitute
n = 500 / ( 4 × 100 )
n = 500 / 400
n = 1.25
Therefore, the coating’s index of refraction is 1.25
2)
given that;
Index of refraction of the coating; n = 1.20
λ = 500 nm
thickness of coating t = ?
t = λ / 4n
we substitute
t = 500 / ( 4 × 1.2 )
t = 500 / 4.8
t = 104.1667 nm
Therefore, the required thickness is 104.1667 nm
an object falls freely from rest the total distance covered by it in 2s will be
Answer:
Distance, S = 19.6 meters
Explanation:
Given the following data;
Time = 2 seconds
We know that acceleration due to gravity is equal to 9.8 m/s².
Also, the initial velocity of the object is equal to zero because it's starting from rest.
To find the total distance covered by the object, we would use the second equation of motion;
[tex] S = ut + \frac {1}{2}at^{2}[/tex]
Where;
S represents the displacement or height measured in meters. u represents the initial velocity measured in meters per seconds. t represents the time measured in seconds. a represents acceleration measured in meters per seconds square.Substituting into the equation, we have;
[tex] S = 0*2 + \frac {1}{2}*(9.8)*2^{2}[/tex]
[tex] S = 0 + 4.9*4[/tex]
[tex] S = 4.9*4 [/tex]
Distance, S = 19.6 meters
Therefore, the total distance covered by the object is 19.6 meters.
A car on the roller coaster begins with 0j of kinetic energy and 12,928j of potential energy and finishes the track with 3,715j of potential energy. How much kinetic energy dose the car finish with????
Answer:
9213 J
Explanation:
Change in Kinetic energy = Change in Potential energy
= 12,928J - 3715J
=9213 J
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Which of the following situations would violate the second law of
thermodynamics?
O A. A heat engine feeling cold after running for an hour
B. A heat engine using heat to do work
O C. A heat engine losing some energy as heat
D. A heat pump being 80% efficient
Answer: it’s A.
Explanation: A pex
The force in a string which is holding up an apple which type of force is it?
Explain why the wave model of light cannot explain the energy emissions from a blackbody
radiator, but the particle model of light can.
HELP MEEE ASAP
Answer:
As the temperature decreases, the peak of the black-body radiation curve moves to lower intensities and longer wavelengths. The black-body radiation graph is also compared with the classical model of Rayleigh and Jeans.
So as you see the wavelengths are in the x axis so all wavelengths are covered.
Black-body radiation provides insight into the thermodynamic equilibrium state of cavity radiation. If each Fourier mode of the equilibrium radiation in an otherwise empty cavity with perfectly reflective walls is considered as a degree of freedom capable of exchanging energy, then, according to the equipartition theorem of classical physics, there would be an equal amount of energy in each mode. Since there are an infinite number of modes this implies infinite heat capacity (infinite energy at any non-zero temperature), as well as an unphysical spectrum of emitted radiation that grows without bound with increasing frequency, a problem known as the ultraviolet catastrophe. Instead, in quantum theory the occupation numbers of the modes are quantized, cutting off the spectrum at high frequency in agreement with experimental observation and resolving the catastrophe. The study of the laws of black bodies and the failure of classical physics to describe them helped establish the foundations of quantum mechanics.
The above explains why the classical assumptions lead to a wrong spectrum.
Explanation:
i don't know if It helps you..parang Ang layo naman Ng sagot ko sa tanong mo
The wave model of light cannot explain the energy emissions from a blackbody radiator, but the particle model of light can be because the electromagnetic wave theory does not explain the black body radiation and the particle model of light can explain it.
What is Black body radiation?Black body radiation is defined as the surface which absorbs all the energy and radiant light falling on it because it absorbs all light of color.
An example of black body radiation is a cavity with a small hole in it.
What is an Electromagnetic Wave ?The Electromagnetic Wave is also called EM Waves which is defined as the waves that are created as a vibration between a magnetic field and electric field.
What is Light ?Light is defined as the electromagnetic radiation which propogates as waves and allows us to make the object visible.
Learn more about the Black Body here: https://brainly.com/question/28887620
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If ATM is 102 kPa, what force does the atmosphere exert on the palm of your hand which has an area of 0.016 meters?
Answer:
Force = 1.632 Newton
Explanation:
Given the following data;
Pressure = 102 kPa
Area = 0.016 m²
To find what force the atmosphere exert on the palm of your hand;
Mathematically, pressure is given by the formula;
[tex] Pressure = \frac {Force}{area} [/tex]
Force = 102 * 0.016
Force = 1.632 Newton
63 km/h is equal to...
O a) 27.5 m/s
b) 18 m/s
c) 1.75 m/s
d) 1.8 m/s
please hurry
Answer:
17.5 m/s
Explanation:
Refer to the attachment!~
12) A negatively-charged balloon touching a wooden wall
A) pulls positive charge on the wall surface toward it.
B) pushes negative charge in the wall away from it.
C) polarizes molecules in the wall.
D) all of the above.
Answer:
D) all of the above.
Explanation:
First polarises it, cahrging and discharging occurs at once.
A negatively charged balloon touching a wooden wall then from the given options option D is correct which is all of the above.
What is a charge?Charged matter experiences a force when it is exposed to an electromagnetic field due to the physical property of electric charge. Positive or negative charges can exist in an electric field (commonly carried by protons and electrons, respectively).
Contrary charges attract one another, while like charges repel one another. A neutral object is one that carries no net charge. Classical electrodynamics, the name given to an early understanding of how charged particles interact, is still accurate for issues that do not call for taking into account quantum phenomena.
In the first step it polarizes molecules in the wall, then charging and discharging in the wall will take place at once.
To get more information about Charge :
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A 620 N physics student stands on a bathroom scale in an elevator that is supported by a cable. The combined mass of student plus elevator is 870 kg. As the elevator starts moving, the scale reads 450 N.
Required:
a. Find the acceleration of the elevator (magnitude and direction).
b. What is the acceleration if the scale reads 670 N?
c. If the scale reads zero, should the student worry? Explain.
d. What is the tension in the cable in parts (a) and (c)?
Answer:
(a) 9.28 m/s2
(b) 9.03 m/s2
(c) 9.8 m/s2
(d) 450 N, 670 N
Explanation:
mass of elevator + student, m = 870 kg
Reading of scale, R = 450 N
(a) When the elevator goes down, the weight decreases.
Let the acceleration is a.
By the Newton's second law
m g - R = m a
870 x 9.8 - 450 = 870 a
a = 9.28 m/s2
(b) R = 670 N
Let the acceleration is a.
870 x 9.8 - 670 = 870 a
a = 9.03 m/s2
(c) If the scale reads zero, it mean the elevator is falling freely. The acceleration is downwards and its value is 9.8 m/s2.
(d) Tension in cable is 450 N and 670 N.
planet smaller than earth but larger than mercury
Answer:
venus......................
What is the current in the 30 resistor?
A. 0.0833 A
B. 12 A
C. 2 A
D. 10 A
Answer:
Explanation:
Step 1) Combine all resistors into an equivalent overall resistor. These are all in series so you just add them up. Req = 10Ω + 20Ω + 30Ω = 60Ω:
Step 2) Using Ohm's Law, I = V/R = 120/60 = 2 A
Now you know how much current is flowing, and that current flows through each resistor the same. So the current in the 30 Ω resistor is 2.00 amps.
Một ô tô khối lượng một tấn chuyển động trên một đường nằm ngang. Hệ số ma sát giữa bánh ô tô và mặt đường là 0,07. Gia tốc trọng trường g=9,8m/s2
a) vẽ và xác định tên các lực tác động lên vật. Viết phương trình chuyển động của vật.
b) nếu ô tô chuyển động đều, xuống dốc có độ dốc 5%. Tính lực kéo của ô tô.
c) nếu ô tô chuyển động đều. Lên dốc có độ dốc 5%. Tính lực kéo của động cơ ô tô
Answer: B
Explanation: because B
What do we mean by a penetrative pass in the game of football?
Answer:
Penetration means forward passes can go through the opposition lines. Once these penetrative passes get through each line, it eliminates the line of players it broke through and leaves the player in possession closer to the opposition goal.
Explanation:
A temperature of 200 degrees Fahrenheit is equivalent to approximately A.93.3 degrees Celsius B. 232 degrees Celsius C. 37.8 degrees Celsius D. 840 degrees Celsius
Answer:
you can use G.oogle for this question.
Answer:
93.3 degrees Celsius.
Explanation:
hoW DO YOU SPELL THIS?
Answer:
Spell what?
Can u please mention that too?
Answer:
what
Explanation: how do you spell what please include this in your next post
Alex pushes on a 2.0 kg book, resulting in a net force of 6.0 N on the book.
What is the acceleration of the book?
A. 12 m/s2
B. 1.5 m/s2
C. 3.0 m/s2
D. 24 m/s2
HELPPPP
Answer:
3.0 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
From the question we have
[tex]a = \frac{6}{2} \\ [/tex]
We have the final answer as
3.0 m/s²Hope this helps you
44. Water from a fire hose knocks over a wooden shed. Compared with the pressure within the water, the pressure exerted against the shed is
a) less.
b) the same.
c) more.
d) nonexistent.
ADvantage of friction
Answer:
1. Friction enables us to walk freely.
2. It helps to support ladder against wall.
3. It becomes possible to transfer one form of energy to another.
4. Objects can be piled up without slipping.
PLEASE HELP How does an object move when it is in linear motion?
in a straight line
up and down
in a circle
to the left
Answer:
In linear motion, the directions of all the vectors describing the system are equal and constant which means the objects move along the same axis and do not change direction. Correct Answer: In a straight line
Explanation:
Answer:
In a straight line. we can also have translational motion which is also a kind of linear motion .
Alcohol consumption slows people's reaction times. In a controlled government test, it takes a certain driver 0.320 s to hit the brakes in a crisis when unimpaired and 1.00 s when drunk. The car is initially traveling at 110.0 km/h. 1) How much farther does the car travel before coming to a stop when the person is drunk compared to sober
Answer:
[tex]\triangle d=21.726m[/tex]
Explanation:
From the question we are told that:
Unimpaired time to hit break [tex]t_i=0.320s[/tex]
Drunk time [tex]t=1s[/tex]
Initial Velocity [tex]v=110km/h[/tex]
Generally the equation for Average velocity is mathematically given by
[tex]V_{avg}=\frac{\triangle d}{\triangle t}[/tex]
Therefore
[tex]\triangle d=v.dt[/tex]
[tex]\triangle d=31.95*(1-0.32)[/tex]
[tex]\triangle d=21.726m[/tex]
A ball is hit at an angle of 300. At what point in its trajectory does this
projectile have the least speed?
A. Just after it was launched.
B. At the highest point in its flight.
C. Just before it hits the ground.
D. Midway between the ground and the highest point.
A ball is thrown horizontally with a speed of 4.0 m/s from a height of 60.0
meters. What is the range of the projectile?
A. 4.00 m
B. 14.0 m
C. 24.0 m
D. 34.0 m
Which has constant velocity?
A.Range
B.Trajectory
C.Projectile
D.Vertical or Horizontal Velocity
Answer:
C. At the highest point of flight.
Explanation:
Given data;
[tex]u_{x} = 4 m/s ,u_{y} = 0, h = 60 m[/tex]
Time of flight,
by third equation of motion ,
[tex]h=\frac{1}{2} gt^{2}[/tex]
[tex]t=\sqrt{\frac{2*60}{9.8} }[/tex]
[tex]t = 3.5 Sec[/tex]
so the range ,
by horizontal component of velocity,([tex]u_{x}[/tex])
R = 4X3.5
R = 14 m
Horizontal component of velocity remain constant in the entire motion.
plsss help me
thank you very much
An object is 70 micrometer long and 47.66 micrometer wide. How long and wide is the object in km
Answer:
The length of the object in kilometer (km) is 70 x 10⁻⁹ km
The width of the object in kilometers (km) is 47.66 x 10⁻⁹ km
Explanation:
Given;
length of the object = 70 micrometer = 70 μm
the width of the object = 47.66 micrometer = 47.66 μm
The length of the object in meter:
70 micrometer = 70 μm = 70 x 10⁻⁶ m
The length of the object in kilometer (km):
70 x 10⁻⁶ m = 70 x 10⁻⁹ km
The width of the object in meters:
47.66 micrometer = 47.66 μm = 47.66 x 10⁻⁶ m
The width of the object in kilometers (km):
47.66 x 10⁻⁶ m = 47.66 x 10⁻⁹ km
If the temperature stays constant, which change would decrease the amount
of thermal energy in an object?
A. Decreasing its density
B. Increasing its velocity
c. Decreasing its mass
D. Increasing its mass
While a mason was working concrete into formwork, the formwork collapses. Who is BEST suites to rectify this problem? Mason Carpenter Project Manager O Construction Technician A device made in a workplace had defects. To address this issue the workshop manager should communicate directly with the workshop
Answer:
1. Carpenter
2. True
Explanation:
While a mason was working concrete into the formwork, the formwork collapses. The best person to rectify this problem is CARPENTER.
This is because it is the job of the Carpenter to design and build formwork, most especially wooden formwork. Formwork is like casing built to receive concrete and reinforcement during construction. Hence, when formwork collapses either due to stress, tension, or improper construction, it is the job of Carpenter to reconstruct the formwork or rectify the problem.
It is TRUE that when a device made in a workplace had defects. To address this issue the workshop manager should communicate directly with the workshop. However, this communication will be an instruction on what to do next, and it usually directs those responsible to take action where necessary. For example, a workshop manager communicates to a carpenter about the need to rectify a chair or table that has a defect.
Two skaters, both of mass 75 kg, are on skates on a frictionless ice pond. One skater throws a 0.4-kg ball at 6 m/s to his friend, who catches it and throws it back at 6.0 m/s. When the first skater has caught the returned ball, what is the velocity of each of the two skaters
Answer:
v = 0.064 m/s
Explanation:
Given that,
The mass of two skaters = 75 kg
The mass of a ball = 0.4 kg
The speed of the ball = 6 m/s
The speed of skater = 6 m/s
We need to find the velocity of each of the two skaters.
Under the values given the moment with respect to the ball and which is subsequently transmitted to people it would be given by:
[tex]P=0.4(6)+0.4(6)\\\\=4.8\ kg-m/s[/tex]
We know that,
P = mv
Where
v is the velocity of each skater.
[tex]v=\dfrac{p}{m}\\\\v=\dfrac{4.8}{75}\\\\=0.064\ m/s[/tex]
So, the velocity of each of the skaters is 0.064 m/s.
CR Physical Science B (GP) 20-21 / 1 Motion
1. A distance-time graph indicates that an object travels 2 m in 2 s and then travels another 80 m during the next 40 s.
What is the average speed of the object?
O 4 m/s
O
2 m/s
O 8 m/s
10 m/s
Answer:
Average speed = total distance traveled / total time traveled
V = (2 + 80) / (2 + 40) = 82 / 42 = 2 m / s
Identify the reactants in the combustion of methane: CH4 + O2 CO2 + O°H
Guys please help me
Answer:
1)[tex]t=2.26\: s[/tex]
2)[tex]S=33.9\: m[/tex]
3)[tex]v=26.77\: m/s[/tex]
4)[tex]\alpha=55.92[/tex]
Explanation:
1)
We can use the following equation:
[tex]y_{f}=y_{0}+v_{iy}t-0.5*g*t^{2}[/tex]
Here, the initial velocity in the y-direction is zero, the final y position is zero and the initial y position is 25 m.
[tex]0=25-0.5*9.81*t^{2}[/tex]
[tex]t=2.26\: s[/tex]
2)
The equation of the motion in the x-direction is:
[tex]v_{ix}=\frac{S}{t}[/tex]
[tex]15=\frac{S}{2.26}[/tex]
[tex]S=33.9\: m[/tex]
3)
The velocity in the y-direction of the stone will be:
[tex]v_{fy}=v_{iy}-gt[/tex]
[tex]v_{fy}=0-(9.81*2.26)[/tex]
[tex]v_{fy}=-22.17\: m/s[/tex]
Now, the velocity in the x-direction is 15 m/s then the velocity will be:
[tex]v=\sqrt{v_{x}^{2}+v_{fy}^{2}}=\sqrt{15^{2}+(-22.17)^{2}}[/tex]
[tex]v=26.77\: m/s[/tex]
4)
The angle of this velocity is:
[tex]tan(\alpha)=\frac{22.17}{15}[/tex]
[tex]\alpha=tan^{-1}(\frac{22.17}{15})[/tex]
[tex]\alpha=55.92[/tex]
Then α=55.92° negative from the x-direction.
I hope it helps you!