A "screen" or even just a set of parallel bars are highly reflective to electromagnetic waves as long as the open spaces are small compared to the wavelengths.
"Grid" dishes work fine ... with less weight and less wind resistance ... for frequencies below about 3 GHz. (Wavelengths of at least 10 cm.)
(I even worked on a microwave system in South America where huge grid dishes were used on a 90-mile link.)
A 12.0 kg object is stationary on a surface that is inclined 30.0° relative to the horizontal. The coefficient of friction is 0.65. Use a free body diagram to determine the magnitude of the force of static friction on the block.
Help please?
Answer:
hope you can understand the calculations
in 4 seconds, a cheetah can run 112 meters. How fast does this cheetah have to be running? A: 448 m/s || B: 28 m/s || C: 56 m/s || D: 36 m/s
Answer:
B: 28m/s
Explanation:
Use the speed formula
Speed =distance / time
Answer:
[tex]\boxed {\boxed {\sf B. \ 28 \ m/s}}[/tex]
Explanation:
If we want to know how fast the cheetah is running, we need to calculate its speed. This is the rate at which an object moves and the formula is distance divided by time.
[tex]s=\frac{d}{t}[/tex]
The cheetah ran 112 meters in 4 seconds.
d= 112 m t= 4 sSubstitute the values into the formula.
[tex]s=\frac{112 \ m}{ 4\ s}[/tex]
Divide.
[tex]s= 28 \ m/s[/tex]
The cheetah's speed is 28 meters per second and choice B is correct.
A capacitor has plates of area 5.25 * 10 ^ - 5 * m ^ 2 which are separated by 3.14 * 10 ^ - 6 * m . What is its capacitance?
Answer:
1.47 x 10^-10
Explanation:
Acellus
The capacitance of the given capacitor is approximately 1.4805 × [tex]10^{(-10)[/tex]F.
The capacitance (C) of a capacitor is determined by the formula:
C = (ε₀ ×A) / d
Where:
C is the capacitance
ε₀ is the permittivity of free space (ε₀ ≈ 8.85 × [tex]10^{(-12)[/tex] F/m)
A is the area of the plates
d is the distance between the plates
Given:
Area of the plates (A) = 5.25 × [tex]10^{(-5)[/tex]m²
Distance between the plates (d) = 3.14 × [tex]10^{(-6)[/tex] m
Using the given values, we can calculate the capacitance:
C = (ε₀ ×A) / d
C = (8.85 × [tex]10^{(-12)[/tex] F/m) × (5.25 × [tex]10^{(-5)[/tex] m²) / (3.14 × [tex]10^{(-6)[/tex]m)
Simplifying the expression:
C = (8.85 × 5.25 × [tex]10^{(-12 - 5)[/tex]) / (3.14 × [tex]10^{(-6)[/tex])
C = (46.4625 × [tex]10^{(-17)[/tex]) / (3.14 × [tex]10^{(-6)[/tex])
C = 14.805 × [tex]10^{(-17 - (-6)}[/tex])
C = 14.805 × [tex]10^{(-11)[/tex]
Using scientific notation, capacitance as:
C = 1.4805 × [tex]10^{(-10)[/tex] F
Therefore, the capacitance of the given capacitor is approximately 1.4805 × [tex]10^{(-10)[/tex] F.
To know more about capacitance
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A circular loop of flexible iron wire has an initial circumference of 165.0 cm, but its circumference is decreasing at a constant rate of 12.0 cm>s due to a tangential pull on the wire. The loop is in a constant, uniform magnetic field oriented perpendicular to the plane of the loop and with magnitude 0.500 T. (a) Find the emf induced in the
Answer:
emf = - 0.622 V
Explanation:
The electromotive force is given by Faraday's law
emf = [tex]- \frac{d \phi }{dt}[/tex]
Ф = B. A
bold indicates vectors
Ф = B A cos θ
in this case it is indicated that the magnetic field is constant and the angle between the magnetic field and the normal to the area is parallel, so the cos 0 = 1
we substitute
emf = [tex]- B \ \frac{dA}{dt}[/tex]
the area of the circle is
A = pi r²
[tex]\frac{dA}{dt} = \pi 2r \ \frac{dr}{dt}[/tex]
emf = B 2π r [tex]\frac{dr}{dt}[/tex]
speed is defined
v = [tex]\frac{dr}{dt}[/tex]
we substitute
emf = - 2π B r v
let's calculate
emf = - 2π 0.5 1.65 π0.12
emf = - 0.622 V
A Star fleet science officer drops a large rock from a height of 1.55 m onto the surface of an alien planet. The rock strikes the ground in 0.230 s. Determine the acceleration of gravity.
Answer:
58.6 m/s²
Explanation:
Applying,
s = ut+gt²/2............ equation 1
Where s = height of the rock, u = initial velocity, t = time, g = accelration due to gravity of the planet.
From the question,
Given: s = 1.55 m, t = 0.23 s, u = 0 m/s (dropped from an height)
Substitute these values into equation 1
1.55 = (0×0.23)+g(0.23²)/2
1.55 = 0.0529g/2
0.0529g = 3.1
g = 3.1/0.0529
g = 58.6 m/s²
Draw a circuit that uses the resistors listed below as well as a 12V battery source. For your circuit, determine (a) the total resistance, (b) the total current, and (c) the total voltage over the entire system.
Answer: hello your questions lacks the required resistor values therefore i will provide a general answer using an example
answer : a) 14 ohms b) 0.86 amps c) 10.32 V
Explanation:
Assuming the resistors are : 3 ohms , 4 ohms and 5 ohms
Voltage source = 12V
Assuming that the Resistors are in series
a) Determine Total resistance
Req = R1 + R2 + R3
= 3 + 4 + 5 = 14 ohms
b) Total current
Ieq = V / Req
= 12 / 14 = 0.86 amps
c) The Total Voltage over the entire system
Vt = ∑ Voltage drops
= ( 0.86 * 3 ) + ( 0.86 * 4 ) + ( 0.86 * 5 )
= 10.32 V
what can electromagnetic and mechanical waves not carry?
Answer:
Water ;)
Explanation:
have a great rest of your day :)
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A boat produces a wave as it passes an aluminum can floating in a lake. Explain why the can merely moves up and down while waves propagate away from the disturbance caused by the boat.
Answer:
Due to waves.
Explanation:
The can merely moves up and down because the movement of the waves that propagate away from the disturbance caused by the boat. The Can has low density due to low mass and high volume which allow the can to float on the surface of water after prevent it from the drowning. The wave moves the can up and down but prevent it from going deep inside the water so we can say that the can moves due to movement of waves in water.
help mee with the workk no link please ·ᴗ·
Explanation: It Should Be 30:60 So If You Simplify It Would Be 1:2
(I think it's The answer I don't Know)
How is the gravitational force similar to the electric force?
Answer:
They are both proportional to the product of their masses and inversely proportional to the square distance between the masses.
What happens to the speed and frequency of a light ray when it passes from glass into water?
The speed decreases and the frequency increases.
The speed decreases and the frequency remains the same.
The speed increases and the frequency increases.
The speed increases and the frequency remains the same.
Answer:
The speed decreases and the frequency remains the same.
Explanation:
Had it for a castle learning assignment, guessed and got it correct.
The speed of a light ray decreases and its frequency remains the same when it passes from glass into water.
What is the speed of light?The speed of light, also known as the velocity of light, is a fundamental constant of nature and is one of the most well-known physical quantities. It is defined as the speed at which electromagnetic radiation (light) travels through a vacuum, which has a constant value of 299,792,458 meters per second (m/s).
This speed is considered to be the fastest that anything can travel in the universe, and it is a critical component in many physical and biological processes. The speed of light is used in a wide range of scientific and technological fields, including optics, electronics, astronomy, and quantum mechanics. It is considered to be a universal constant and does not change with time, distance, or the medium through which it travels.
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A lamp has a current of 2.0 amperes at 6.0 volts. What is the resistance of lamp?
Answer: B 3.0
Explanation:
a volleyball player has spiked the ball. At the instant the ball leaves her hand, it is 2.6 m above the ground and has an initial vertical velocity of -20 m/s. How long will it take the ball to strike the ground if the opposing team doesn't block it?
Answer: 29.48 s
Explanation:
Given
The initial height of the ball is [tex]h=2.6\ m[/tex]
The ball leaves with an initial velocity of [tex]u=-20\ m/s[/tex]
Using the equation of motion
[tex]h=ut+\dfrac{1}{2}at^2\\\text{Insert the values}\\\\2.6=20\cdot t+\dfrac{1}{2}\times 9.8\times t^2\\\\\Rightarrow 9.8t^2+20t-5.2\\\\\Rightarrow t=\dfrac{-20\pm \sqrt{20^2-4\times 9.8\times (-5.2)}}{2\times 9.8}\\\\\Rightarrow t=\dfrac{-20\pm 603.84}{19.8}\\\\\Rightarrow t=29.48\ s\quad [\text{Neglecting negative t}][/tex]
Therefore, it take 29.48 s for ball to reach the ground.
Plastics are used in millions of objects we use every day. Why are plastics NOT considered natural resources?
A. They are recyclable.
B. They are made by people. C. They are bad for the environment.
D. They are made entirely from nonrenewable resources.
Answer:
letter C. they are bad for the environment
It takes 6s for a stone to fall from the top of a building to the ground calculate i.the height of the building ii.the speed of the stone just before it strikes the ground (g=10ms^-2
Answer:
fffffff
Explanation:
Force F=5 N acts to the right
Answer:
Calculations involving forces
The resultant force is the single force that has the same effect as two or more forces acting together.
Two forces in the same direction
Two forces that act in the same direction produce a resultant force that is larger than either individual force.
You can easily calculate the resultant force of two forces that act in a straight line in the same direction by adding their sizes together.
Example
Two forces, 3 N and 2 N, act to the right. Calculate the resultant force.
Two arrows, one above the other, both pointing to the right, one labelled 2 N and one labelled 3 N. Then an equals sign and then another arrow to the right labelled 5 N.
Two forces acting in the same direction
Resultant force F = 3 N + 2 N = 5 N to the right.
The resultant force is 5 N to the right.
Two forces in opposite directions
Two forces that act in opposite directions produce a resultant force that is smaller than either individual force.
To find the resultant force subtract the magnitude of the smaller force from the magnitude of the larger force.
The direction of the resultant force is in the same direction as the larger force.
Example
A force of 5 N acts to the right, and a force of 3 N act to the left.
Calculate the resultant force.
Two arrows, one above the other, one pointing to the left, labelled 2 N, the other pointing to the right labelled 3 N. Then an equals sign, with an arrow to the right labelled 1 N.
Two forces acting in opposite directions
Resultant force F
Resultant force F = 5 N - 3 N = 2 N to the right.
The resultant force is 2 N to the right.
Explanation:
Thanks me later
The graph shows the layers of Earth's atmosphere. Which statement best describes the relationship between temperature and altitude in the atmosphere?
A. The relationship between temperature and altitude is variable and unpredictable.
B. Overall, the temperature of the atmosphere increases with altitude.
C. The relationship between temperature and altitude is different in each zone of the atmosphere.
D. Temperature decreases with altitude until the stratosphere is reached, and then it increases from there.
Answer:
The best statement which describe this is actually:
D. Temperature decreases with altitude until the stratosphere is reached, and then it increases from there.
Explanation:
From the graph shown, it could be seen that, temperature decrease with height. The higher the height, the lower the temperature. For example, from the graph, when the height was around 50 km, the temperature was within the range of -10⁰C to 0⁰C. On the other hand, when the height increases around 78 km, the temperature decreases to the range of to -70 ⁰C to -80⁰C
Can someone help me please??
Which is not true about the role of gravity in the formation of planets?
A. Dust and gas particles that were attracted to each other began to rotate into a protoplanetary disk.
B. Gravity between planetesimals caused them to join together into conglomerate clumps.
C. Our solar system is the only place in the universe where gravity played a key part in the formation of planets.
D. Gravity of larger objects in orbit around the sun attracted, and cleared the orbital path of, smaller planetesimals, gas, and dust.
24. ____
Choose the most accurate description of the dimensions of our solar system:
a. The planets are approximately the same size as each other, and orbit at evenly-spaced distances from the sun.
b. Rocky planets are small, dense, and orbit relatively close to the sun, compared to the Jovian planets, which are large, less dense, and orbiting far from the sun.
c. Rocky planets alternate with gas giants as they orbit at even intervals from the sun
d. Gas planets are small, orbiting relatively close to the sun, while large, dense rocky Giants
orbit the sun at great and varying distances.
25. ____ A new object was discovered in the Kuiper Belt. At 6 billion km from the sun, it could be the newest dwarf planet. How many AU is it from the sun? Use 150,000,000 km as Earth’s orbital distance.
a. 90AU b. 9AU c. 400AU d. 40AU
1. Our solar system is the only place in the universe where gravity played a key part in the formation of planets.
2. Rocky planets are small, dense, and orbit relatively close to the sun, compared to the Jovian planets, which are large, less dense, and orbiting far from the sun.
3. _______
I need help please and thanks
Answer:
4.Given:
m=1000kg
a=(3m/s)^2
F=m×a
=1000×3
=3000N
5.Given:
m=50kg
a=(5m/s)^2
F=m×a
=50×5
=250N
6. Given
F=250N
a=(5m/s)^2
m=?
F=m×a
250N=m×(5m/s)^2
m×(5m/s)^2=250N
m=250N÷(5m/s)^2
m=50kg
Justin mixed two cups of lemon juice and two cups of sugar with a gallon of water in a pitcher. What happened to the lemon juice, sugar, and water?
Answer:
The correct answer is - Lemon juice hydrolyzes sugar and dissolves it faster and creates a solution.
Explanation:
When mixing lemon juice and sugar in water are mixed together, the lemon juice dissolves the sugar faster as it has citric acid that hydrolyzes sucrose molecules of sugar in glucose and fructose.
This mixing of all three lemon juice, water, and sugar form a solution. Here in this solution, water is solvent, and sugar and lemon juice are solutes. The quantity of all three determined the nature of the solution if it will be acidic or more diluted.
A particle is accelerated uniformly from rest, so that after 10 seconds it has achieved a speed of 15 m/s. Find its acceleration.
Answer:
1.5 m/s²
Explanation:
Applying,
a = (v-u)/t ...................... Equation 1
Where a = acceleration of the particle, v = final velocity of the particle, u = Initial velocity of the particle, t = time.
From the question,
Given: u = 0 m/s (From rest), v = 15 m/s, t = 10 seconds
Substitute these values into equation 1
a = (15-0)/10
a = 15/10
a = 1.5 m/s²
Astronomers have measured that there is more helium in the universe than can be explained by the fusion in stars over the last 13 billion years. How do they think the extra helium got into the universe
Answer:
From big bang and stars.
Explanation:
The extra helium got into the universe through big bang and fusion reaction that occur in stars. Our universe formed about 13.7 billion years ago with big explosion, this event is known as big bang. The fusion of hydrogen nuclei in the stars produces helium and energy so we can say that most of the extra helium got into the universe through fusion reaction that occur in the stars continuously.
As a sound wave changes from one to another, it will often be refracted.A. frequency B. amplitude C. medium D. wavelength?
Answer: the answer is medium
Explanation:
Question 2 (1 point)
What would change if you brought at 100.0 kg cannon ball to the moon?
Mass
оа
Ob
ос
Weight
both
Od
neither
А
man of mass
77kg stands on a
Spring-weighing
Machine
inside a lift
When the lift starts to ascend, its accel-
eration 2 m/s2. what will be reading on.
the machine?
Explanation:
The reading on the scale is
W = m(g + a)
= (77 kg)(9.8 m/s^2 + 2 m/s^2)
= 908.6 N
The emission spectrums are known for the elements below.
What elements are in the unknown sample?check all that apply
Answer: Hello your question is incomplete, I was able to find the question online but I am unable to attach it due to plagiarism rules
answer : Lithium and Potassium
Explanation:
The elements that are in the unknown sample are : Lithium and Potassium
An Emission spectrum is used to determine the composition of a material and it is distinctively different for each element that us found on the period table
Please help the right answer get the Brainly and this is physical science btw
Sadie rides her bike 1600 m East and then turns around and goes 800 m
West. What is her displacement?
Answer:
(1600 m east) + (800 m west) = (800m east)
Her displacement is 800 m east.
Explanation:
Displacement is the distance and direction between the starting point and ending point,regardless of the route traveled between them.
PLS ANSWER QUICK I HAVE A COUPLE MINUTES.
An object moves through space with balanced forces acting on it. Which statement
best describes the speed and direction of the object as long as the forces acting on it
remain balanced?
A. The speed and direction of the object will both change.
B. The speed and direction of the object will remain constanti
C. The speed will change, but the direction will remain constant.
D. The speed will remain constant but the direction will change
Answer:
B
Explanation:
Newton's first law of motion states that every object will continue in a state of rest or uniform motion in a straight line unless a resultant force acts on it
balanced force means resultant force is 0N
this means that the speed will not change as it uniform and the direction will not change because it will continue at the same speed in a statight line and direction
sorry man, I think it was late
hope this helps
Which statement best explains why there could be a force of attraction
between two electrically charged objects?'
because they have like charges
because they have unlike charges
because they have the same number of protons
because they have the same number of electrons