Answer:
2)primary mirror
Explanation:
A reflecting telescope contains mirrors and a refracting telescope contains lenses. There are two mirrors in basic reflecting telescope. The primary mirror gathers the light from the bodies at distance and reflects it towards the secondary mirror. The secondary mirror is placed at such an angle that it then reflects the light towards the eye piece and we can observe the faraway body.
Answer:
B. Primary mirror
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
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.
what are the first 20 elements and their chemical symbols
What is the VR if a slope of length 20 m that rises
to a height of 5 m?
Answer:
vR= effort distance/ load distance
VR = height / length
VR. = 5/20
VR = 0.25
Which type of wave is more dangerous for humans? Microwaves or x-rays?
Answer:
x-rays
Explanation:
Water at the Antarctica usually exits as ice, making it very difficult to use the water or conduct experiment requiring the water to be in liquid state. A coffee addicted physicist stationed at a research base requires about 0.8 kg of ice for his coffee on the hour. a. How much heat is required to convert 0.8 kg of ice at -35 "C into steam at 100 C7 b. Plot the temperature - energy graph for the processes in (a). 5] [5] c. The surface tension of water was determined in a laboratory by using the drop weight method. 100 drops were released from a burette the inner diameter of whose opening is 1.8 mm. The mass of the droplets was 3.78 g. 1. Determine the surface tension of the water and comparing it with the tabulated value, i. Calculate the relative error of the measurements: [6] [4]
Answer:
water or conduct experiment requiring the water to be in liquid state. A coffee
addicted physicist stationed at a research base requires about 0.8 kg of ice for
his coffee on the hour.
a. How much heat is required to convert 0.8 kg of ice at -35 °C into steam
at 100°C?
[5]
b. Plot the temperature - energy graph for the processes in (a). [5]
C. The surface tension of water was determined in a laboratory by using
the drop weight method. 100 drops were released from a burette the
inner diameter of whose opening is 1.8 mm. The mass of the droplets
was 3.78 g.
i. Determine the surface tension of the water and, comparing it
with the tabulated value,
161
ii. Calculate the relative error of the measurements.
Many automatic processes use circuits to accomplish a task. Thermostats, automatic light switches, motors, and home security systems all use circuits. Besides common electronic devices such as stereos, iPods, computers, cell phones, video games, TVs, DVD players, what other things in our world use circuits?
Answer:
homes and cars
Explanation:
There are many devices in our day to day lives that use circuits in order to function. Aside from all those that are listed in the question some others include, our entire homes and cars, with the main difference being the amount of voltage that is being used. Just like tv's and computers, houses and cars use electrical circuits on a much larger scale in order to provide electricity to different parts of the system.
The diagram shows the results when two parents are
crossed. The letters represent alleles for a trait that is
controlled by three different genes.
Which best describes this inheritance pattern?
multiple allele because a trait is controlled by three different genes
polygenic because the offspring have alleles from both parents
multiple allele because the offspring have alleles from
both parents
polygenic because a trait is controlled by three different
genes
Answer:
Polygenic because a trait is controlled by three different genes
Explanation:
In the given question, the diagram of the question is not found anywhere therefore the question has been answered based on previous knowledge.
The traits of an organism are determined by the sequences of nucleotide present on the DNA called genes. One gene-one protein hypothesis suggests that usually one trait is determined by 2 alleles of a gene but there are few traits which are either determined or influenced by more than one gene.
These traits are known as the polygenic trait as the traits are controlled by more than one or "poly (many) genes" like human eye color, height, and others.
Thus, the selected option is the correct answer.
Answer:
Polygenic because a trait is controlled by three different genes
Explanation:
got 100%
At t= 0, a particle moving in the xy plane with constant acceleration has a velocity of Vi= (3.00i -2.00j) m/s and is at the origin. At t= 3.00 s, the particle's velocity is V = (9.00i + 7.00j) m/s . Find (a) the acceleration of the particle and (b) its coordinates at any time t.
Answer:
(a) a = (2i + 4.5j) m/s^2
(b) r = ro + vot + (1/2)at^2
Explanation:
(a) The acceleration of the particle is given by:
[tex]\vec{a}=\frac{\vec{v}-\vec{v_o}}{t}\\\\[/tex]
vo: initial velocity = (3.00i -2.00j) m/s
v: final velocity = (9.00i + 7.00j) m/s
t = 3s
by replacing the values of the vectors and time you obtain:
[tex]\vec{a}=\frac{1}{3s}[(9.00-3.00)\hat{i}+(7.00-(-2.00))\hat{j}]\\\\\vec{a}=(2\hat{i}+4.5\hat{j})m/s^2[/tex]
(b) The position vector is given by:
[tex]\vec{r}=\vec{r_o}+\vec{v_o}t+\frac{1}{2}\vec{a}t^2[/tex]
where vo = (3.00i -2.00j) m/s and a = (2.00i + 4.50j)m/s^2
does earths surface heat up the same everywhere
the correct answer is no ;)
Answer:
. .
Explanation
. .
.
(0) Calculate the momentum of the vehicle when it moves at the maximum speed of 90 km/h with load of 3000 kg
Answer: [tex]75000kg*m/s[/tex]
Explanation:
[tex]p=mv[/tex]
where;
p = momentum
m = mass = 3000kg
v = velocity = 25m/s
--------------------------------------------------------------------------------------------------
The first thing we need to do is convert 90km/h to m/s. Our conversion factors here are: 1km = 1000m and 1h = 3600s
[tex]90km/h(\frac{1000m}{1km})(\frac{1h}{3600s} )=25m/s[/tex]
Plug your values in the formula:
[tex]p=(3000kg)(25m/s)\\p=75000kg*m/s[/tex]
Which aspect of health is best illustrated by the following example? I work well in a group and
respect my other classmates.
O social
O physical
O emotional
A positive test charge of 8.5 × 10 negative 7 Columbus experiences a force of 4.1 × 10 negative 1 N calculate the electric field created by the positive test charge also specify the direction of the electric field with respect to the force
Explanation:
direction of electric field is same as that of force experienced by the test charge
Answer:
Comments/Reasoning Calculations/Results
I used the equation for calculating electric field strength. E = F/q
I substituted the values of F and q in the equation to get
this value of E E= (4.1 x10-1)/(8.5 x10-7)
The electric field strength is 4.8 × 105 newtons/coulomb
Explanation:
edmentum sample answer
battery of 12 V supplies charge of 1000 C to a device work battery
Answer:
Work done is 12000 J
Explanation:
We have,
Voltage of a battery is 12 V
Charge supplied by the battery is 1000 C
Let us assume to find the work is done by the battery in moving the charge. The work done is given in terms of voltage as :
[tex]W=qV\\\\W=1000\times 12\\\\W=12000\ J[/tex]
So, the work of 12000 J is done by battery in moving charges.
Rachel is looking at a swamp. She sees sandhill cranes swooping by, algae on a pond, small snails, fungi, and some fish. Explain how the organisms Rachel sees are connected and how they all help the swamp ecosystem thrive.
Answer:
The organisms Rachel see are all inter dependent on one another to survive in the form of a food chain. This relationship helps the swamp ecosystem thrive.
Explanation:
In this swamp ecosystem, the Sandhill crane relies on the fishes for food, Some of the fishes rely on the algae or the snail for food and the snail also rely on the algae for food. This relationship not only serves to nourish the organism above the food chain but serves a general purpose of controlling the ecosystem. The absence of one or more of these organisms, say the algae can offset the ecosystem in a chain reaction that might go as far as affecting the cranes. Also, the absence of algae feeders can lead to an algae boom which might overpower the oxygen concentration in the pond further killing other organisms in the pond that need oxygen for respiration.
A green light has a wavelength of 485 nm.
What is its frequency? (1 nanometer is 10-9 m)
Answer:
Explanation:
C bro
What type of wave does NOT need matter to carry energy? *
1 point
Sound wave
Ocean wave
Electromagnetic wave
Answer:
I guess sound wave I s gonna be d right answer
Explanation:
cos sound doesnt has weight and occupies space
Answer:
Electromagnetic wave
Explanation:
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.
Arrange the movement/act/organization in ascending order of occurrence. Energy Supply and Environmental Coordination Act Nature Conservancy Intergovernmental Panel on Climate Change (IPCC) Clean Water Act Federal Water Pollution Control Act Eastern Wilderness Act Water Quality Act Toxic Substances Control Act Clean Air Act Endangered Species Preservation Act ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓ ↓
Answer:
PLATO!!!!! THESE ARE RIGHT!!! OTHERS ARE NOT CORRECT. I JUST GOT IT RIGHT ON PLATO
Explanation:
1. federal water pollution control act
2.nature conservancy
3. clean air act
4. water quality act
5. endangered species preservation act
6. clean water act
7. energy supply and environmental coordination act
8. eastern wilderness act
9. toxic substance act
10. intergovernmental panel on climate change (IPCC).
which of the following is a surface phenomenon A evaporation B boiling C melting D freezing
Answer:
A. evaporation
Explanation:
Evaporation is a surface phenomenon as the molecules of the surface gets sufficient energy to overcome the force of attraction which will help in converting to the vapor phase.
which of the following is greater:A.7.8grams per millilitre or 4.1 microgram per microlitre
B.3×10¬²kilograms/cm³ or 3×10¬1 milligrams/cm³
Answer:
A : 7.8 grams per millilitre
B : 3×10^-2 kilograms/cm^3
A wave travels an average distance of 6 meters in 3 seconds. What is the wave's velocity?
Answer:
2m/s
.................
Which scientist was the first to propose the heliocentric model of the universe?
Answer:
Nicolaus Copernicus
-He was a Mathematician
Explanation:
HIIIIII I NEED HELPPPPPP
You may choose to answer them all, but if you'd like, just answer a few of them :)
1. The unit of electric potential or electromotive force is the _____.
volt
ohm
ampere
franklin
2. In a circuit, a battery is used to _____.
conduct current
slow down current
raise the potential of electrons
convert electrical energy to some other form of energy
3. Why is current supplied to consumers from generating plants in the form of alternating current?
Direct current cannot be generated in the amount necessary to supply enough consumers.
It is a much more efficient mode of transmitting electricity than direct current.
This is the only form that current can be transmitted over the long distances.
It is way too dangerous to transmit direct current to consumers' homes.
4. When you turn on a television, the electrical circuit _____.
closes
opens
does not move
Answer:
voltraise the potential of electronsIt is a much more efficient mode of transmitting electricity than direct current does not moves
3. If the tyre of a car has a diameter of 0.7 m and if the wheel has an angular velocity of 10 radians per second, what is the speed of the car in m/s
Answer:
speed = radius x angular velocity
= 0.7/2 x 10
= 3.5 m/s
Which statement is true about the loudness of a sound?
A.) it is directly proportional to the distance of the listener from the source.
B.) it is inversely proportional to the square of the distance of the listener from the source.
C.) it is directly proportional to the square of the distance between the listener from the source.
D.) it is inversely proportional to the distance between the listener from the source.
Answer:
The Answer is B
Explanation: The loudness is shared among the listener and source
Answer : The correct option is, (B)
Explanation :
There is a direct relation between the loudness of sound and the intensity of sound.
[tex]L=10 log \frac{I}{Ia} }[/tex] ..........(1)
where,
L = loudness of sound
I = intensity of sound
= intensity of reference
From this we conclude that the loudness is directly proportional to the intensity of the sound.
There is an indirect relation between the intensity of sound and the distance of the listener from the source.
[tex]\frac{I_1 }{I_2 } = (\frac{d_1}{d_2} )^{2}[/tex] ...................(2)
From this we conclude that the intensity of sound is inversely proportional to the square of the distance of the listener from the source.
From equation (1) and (2) we conclude that the loudness of sound is inversely proportional to the square of the distance of the listener from the source.
Hence, the correct option is, (B)
How do we know what is inside of Earth ?
Answer:
Most of what we know about the interior of the Earth comes from the study of seismic waves from earthquakes. Seismic waves from large earthquakes pass throughout the Earth. These waves contain vital information about the internal structure of the Earth.
Calculate the pressure in pascals if a 140N force is applied to an area of 0.1m².
Answer:
Pressure = 1400 pascals
Explanation:
The formula to measure pressure is Pressure equals force in pounds over the area in square inch. The written abbreviated formula is P= F/A. By looking at the formula one can see that top obtain the pressure on an object, one must divide the the force by the area of an object.
P = 140/0.1
P = 1400
[tex]\\ \rm\longmapsto Pressure=\dfrac{Force}{Area}[/tex]
[tex]\\ \rm\longmapsto Pressure=\dfrac{140}{0.1}[/tex]
[tex]\\ \rm\longmapsto Pressure=1400Pa[/tex]
who is the founder of pelincilin
Answer:
Alexander Fleming
Explanation:
the founder of pelincilin is Alexander Fleming
state any differences between Mass and weight
Answer:
The difference between mass and weight is that mass is the amount of matter in a material, while weight is a measure of how the force of gravity acts upon that mass. Mass is the measure of the amount of matter in a body. ... Weight usually is denoted by W. Weight is mass multiplied by the acceleration of gravity.
Answer:
mass is present in the substance and weight is the force exerted by gravity