1/2 × 2 × pie × radius
= pie × radius
When 120 V is applied across a 20 m long wire, the magnitude of the current density was found to be 2 * 10 ^ 8 * A / (m ^ 2) . The resistivity of this wire is
Answer:
[tex]\rho=3\times 10^{-8}\ \Omega-m[/tex]
Explanation:
Given that,
Voltage, V = 120 V
The length of the wire, l = 20 m
The current density of the wire, [tex]\dfrac{I}{A}=2\times 10^8\ A/m^2[/tex]
We need to find the resistivity of this wire. We know that,
[tex]R=\rho \dfrac{l}{A}[/tex]
Where
[tex]\rho[/tex] is the resistivity of wire
Also, [tex]R=\dfrac{V}{I}[/tex]
So,
[tex]\dfrac{V}{I}=\rho \dfrac{l}{A}\\\\\rho=\dfrac{V}{l\dfrac{I}{A}}[/tex]
Put all the values,
[tex]\rho=\dfrac{120}{20\times 2\times 10^8}\\\\=3\times 10^{-8}\ \Omega-m[/tex]
So, the resistivity of this wire is equal to [tex]3\times 10^{-8}\ \Omega-m[/tex].
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According to "Take a Closer Look", what type of lens is used to correct nearsightedness?
Answer: A.) concave lens
Explanation: i hope this helps shawtay :)
In general, a concave lens (also known as a diverging lens) is used to correct nearsightedness, as stated in "Take a Closer Look." Option C is correct.
What is the lens?A lens is an optical component that is used to refract (bend) and focus light. It is typically made of a transparent material, such as glass or plastic, and has a specific shape that allows it to alter the path of light as it passes through.
Here,
In general, a concave lens (also known as a diverging lens) is used to correct nearsightedness, as stated in "Take a Closer Look."
A concave lens is thinnest at the center and thicker at the edges, which causes light rays passing through the lens to diverge or spread out. By placing a concave lens in front of a nearsighted eye, the lens causes incoming light rays to diverge more before they reach the eye's lens, which then focuses them properly on the retina, resulting in clearer vision.
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Un vehículo que desciende hacia la luna tiene una velocidad vertical hacia la superficie de la luna de 35 m/s. Al mismo tiempo, tiene una velocidad horizontal de 55m/s. ¿Cuál es la velocidad del vehículo en su trayectoria de descenso? ¿Qué ángulo forma la trayectoria con la vertical?
Answer:
1. La velocidad del vehículo en su trayectoria de descenso es 65.2 m/s.
2. El vehículo forma un ángulo de 57.5° con la vertical.
Explanation:
1. La magnitud de la velocidad del vehículo está dada por la suma de las componentes del vector en la dirección vertical (y) y horizontal (x):
[tex] v^{2} = v_{x}^{2} + v_{y}^{2} [/tex]
[tex] v = \sqrt{v_{x}^{2} + v_{y}^{2}} = \sqrt{(55 m/s)^{2} + (35 m/s)^{2}} = 65.2 m/s [/tex]
Entonces, la velocidad del vehículo en su trayectoria de descenso es 65.2 m/s.
2. El ángulo que forma la trayectoria con la vertical se puede calcular con trigonometría:
[tex] tan(\theta) = \frac{v_{x}}{v_{y}} [/tex]
[tex] \theta = tan^{-1}(\frac{v_{x}}{v_{y}}) = tan^{-1}(\frac{55}{35}) = 57.5 ^{\circ} [/tex]
Por lo tanto, el vehículo forma un ángulo de 57.5° con la vertical.
Espero que te sea de utilidad!
All electric charge is based on the what in Atoms
Answer:
c. Protons and electrons
Explanation:
electrons carry out negative charge
protons carry out positive charges
Why do you see a rainbow when you look at white light through a prism?
please don't send links or files
Group of answer choices
components of white light (colors) were refracted into different amounts by the prism.
different colored of atoms passed through the prism and were knocked out.
the white light’s energy was diverted and converted into visible light.
the prism converted ultraviolet light to visible light.
Answer:
Sunlight is a mixture of colors. When it passes through a glass prism, some of the light is bent, or refracted, more than other portions. And just as sunlight passing through a prism is bent, so is sunlight passing through drops of water. This produces an atmospheric solar spectrum in the sky for all to see: a rainbow.
Explanation:
Madeline is measuring wavelengths. Look at her notes above. What mistakes has she made in her measurement? What should she do differently to obtain the correct wavelength?
A conducting bar moves along a circuit with a constant velocity. A constant magnetic field is perpendicular to the bar and circuit. The bar has covered 13.00 m2 of area by a certain time and then 15.60 m2 1.00 second later. The average EMF induced in the circuit over the 1.00 second time interval is 1.30 V. What is the strength of the magnetic field?
Answer:
0.500 T
Explanation:
Since the change in time and the number of coils are both 1, I set the problem up to be 1.3=(1.5(x)-13(x)). I then plugged in numbers for x until I got the answer to be 1.3 V.
Help me please!!!!!!!!!!
Answer:
B because 17100 is the half of the carbon
You are not allowed to park within
feet of any flashing signal, stop sign, or traffic signal.
30
20
15
10
Answer:
The correct answer is - 30 feet.
Explanation:
According to the parking laws one should not park within 30 feet of any flashing signal, stop sign, or traffic signal it is not allowed. Parking is also not allowed in case of the following situations -
On crosswalks
In front of driveways
double parking
On sidewalks.
at "No Parking" signs are posted.
Within intersections or 20 feet of an intersection.
Within 15 feet of a fire hydrant.
Answer:
30 ft
Explanation:
You are not allowed to park within 30 feet of any flashing signal, stop sign, or traffic signal.
An object is travelling in a straight line. The diagram is the speed-time graph for
the object.
At which labelled point is the object accelerating at a changing rate?
The point on the graph that object is accelerating at a changing rate is point A.
What is acceleration?
Acceleration of an object is the rate of change of velocity with time.
a = Δv/Δt
where;
Δv is change in velocityΔt is change in timeThus, the point on the graph that object is accelerating at a changing rate is point A.
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What type of material are magnets usually made of
Answer:
They come from metal elements or alloys.
Explanation:
Different materials produce magnets of varying strengths. Ceramic magnets, also known as ferric magnets, are made of iron oxide in a ceramic composite. Samarium cobalt magnets are created from the combination of cobalt and samarium, which is a rare-earth element. Neodymium magnets contain boron, iron and neodymium, also a rare-earth element. The strongest naturally occurring magnet is lodestone, a form of magnetite. It attracts even small objects, such as staples and paper clips.
A 12 kg ball is rolling with a velocity of 10 m/s. How much kinetic energy does the ball have?
Answer:
kinetic energy = 1/2 x mass x velocty^2
1/2(12)(10^2)
600 N
hope that answers your question
Explanation:
Would you expect to weigh more on an ocean beach or on top of a mountain? Explain.
Answer:
I think top. of a mountain
Answer: You would weigh very slightly more at sea level than at the top of a mountain, not enough for you to notice, but a measurable amount. Weight, which really means gravitational force, is proportional to the product of the masses of two objects acting on each other, in this case the giant earth and the minuscule you.
Explanation:
A bus is traveling at 60 miles/hour east. Determine the velocity of the following objects using the bus as the frame of reference:
• A car traveling at 60 miles/hour east?
• A truck traveling at 65 miles/hour west:?
Answer:
a) v'=0 , B) v'= 125 miles/h
Explanation:
This is a relative speed exercise, the speed of a body is
v ’= v - u
where v is the speed with respect to the Earth and u the speed of the reference frame with respect to which we want to calculate
a) with respect to a car traveling east at u = 60 miles / h
v ’= 60 -60
v ’= 0
with respect to this vehicle the speed of the car is zero
b) with respect to a truck traveling west at u = -65 miles / h
v = 60 - (-65)
v = 125 miles / h
what will be the value of g if both masses are halved?
Answer:
f/4
Explanation:
Explanation: Gravitational force between two objects varies directly as their masses and inversely as the square of the distance between them. So, when the masses of both objects are halved without changing the distance, the gravitational force between them would become one-fourth of the original value
What element is formed in the following nuclear reaction
Answer:
Oxygen or more precisely, the O-15 isotope.
A wire lying along a y axis form y=0 to y=0.25 m carries a current of 2.0 mA in the negative direction of the axis. the wire fully lies in a magnetic field given by (0.3y)i + (0.4y)j Tesla. what is The magnetic force on the wire
A: (0.15i+0.2j) N
B: (0.0015i+0.002j) N
C: (-6.25E-5 k) N
D:(6.25E-5 k) N
E: None of the above
Answer:
E: None of the above
Explanation:
Since the force on the wire F = ∫idL × B where i = current in wire = 2.0 mA = 2.0 × 10⁻³ A, dL = vector length of wire = dyj and we integrate from y₁ = 0 m and y₂ = 0.25 m, and B = magnetic field = (0.3y)i + (0.4y)j
So, F = ∫idL × B
and we integrate from y₁ = 0 m and y₂ = 0.25 m
F = 2.0 × 10⁻³ A∫₀⁰°²⁵[dyj m × (0.3y)i + (0.4y)j]
F = 2.0 × 10⁻³ A∫₀⁰°²⁵[dyj m × (0.3y)i + dyj m × (0.4y)j]
F = 2.0 × 10⁻³ A∫₀⁰°²⁵[(0.3y) × dy(j × i) + 0.25 × (0.4y)(j × j)]
F = 2.0 × 10⁻³ A∫₀⁰°²°⁵[(0.3ydy(-k) + 0.1y)(0)]
F = 2.0 × 10⁻³ A∫₀⁰°²⁵(-0.3ydy)k
F = 2.0 × 10⁻³ A[-0.3y²/2]₀⁰°²⁵k
F = -2.0 × 10⁻³ A[0.3(0.25)²/2 - 0.3(0)²/2]k
F = -2.0 × 10⁻³ A[0.3(0.0625)/2 - 0]k
F = -2.0 × 10⁻³ A[0.3(0.0625)/2]k
F = -1 × 10⁻³[0.01875]k N
F = -[0.01875 × 10⁻³]k N
F = -[1.875 × 10⁻⁵]k N
Since the answer is not contained in the options, the answer is E.
true or false? rocks have organic materials and fossil remains in them
Answer:
trueeeee
Explanation:
Marine science- question- what is climate change?
Answer:
Defined below
Explanation:
Climate change is simply the long term change in the average weather patterns that are associated with the local, regional and global climates of the earth. Climate change is usually driven by human activities like burning of fossils; natural processes like cyclic ocean patterns; external factors like volcanic eruptions.
A sound wave is moving through air. The wave has a wavelength of 0.65 m and a frequency of 512 Hz. Calculate the speed of the wave.
Answer:
"332.8 m/s" is the right solution.
Explanation:
The given values are:
Wavelength,
[tex]\lambda=0.65 \ m[/tex]
Frequency,
[tex]f = 512 \ Hz[/tex]
As we know,
⇒ [tex]Speed=Frequency\times Wavelength[/tex]
or,
⇒ [tex]V=f\times \lambda[/tex]
By putting the given values in the above relation, we get
⇒ [tex]=512\times 0.65[/tex]
⇒ [tex]=332.8 \ m/s[/tex]
The wavelength of a wave is 8 m. The period of the wave is 2 seconds. What is the velocity of the wave?
Explanation:
[tex] \lambda = 8 \: m \\ T = 2 \: s \\ but \: f = \frac{1}{T} \\ f = \frac{1}{2} = 0.5 \: Hz \\ from \: wave \: equation \\ V = f \lambda \\ V = 8 \times 0.5 \\ V = 4 \: m {s}^{ - 1} [/tex]
If another vehicle is trying to pass your vehicle,
your speed
Increase
Maintain
<
Ignore
Reduce
Answer:
Reduce you're speed, and let the other vehicle pass you
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The following map was created using modern technology to determine the overall temperature change of the oceans. What can be concluded about the relationship between temperature and salinity from the map? (10 points)
Group of answer choices
Areas of water with higher precipitation have a greater salinity.
Decreasing temperatures evaporate water slowly, causing an increase in salinity.
Increasing temperatures evaporate water faster, causing an increase in salinity.
The areas of water without temperature changes will have a greater salinity.
Answer:
Increasing temperatures evaporate water faster, causing an increase in salinity.
Explanation:
When the water molecules of the ocean become heated, they expand. ... Since warmer water thus can hold more salt and other molecules than cold water; it can have a higher salinity.
The correct option is C, increasing temperatures cause faster evaporation of water which results in an increase in salinity.
What does the map represent?Due to the link between ocean temperature and salinity, this map of ocean temperature can easily be compared to a map of ocean salinity.Salinity rises as water temperature rises, and vice versa: the lower the water's temperature, the higher the salinity. The Timor Sea, Arafura Sea, and the northern portion of the Coral Sea can all be seen on this map as having higher temperatures than most of the nearby waters. These regions' shallow water and proximity to the equator, as well as the influence of warm ocean currents, are the main causes of these higher temperatures. In turn, that would imply that they experience greater water evaporation, which adds to greater salt concentration, resulting in more salinity in the water than in other locations.Hence we can conclude that as the temperature rises, the process of evaporation takes place more rapidly which decrease the concentration of salt in water, which leads to higher salinity.
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Martin rides his motorcycle at 20 m/s. suddenly he sees a row of stones
blocking the road 170 m ahead. He applies the brakes and the motorcycle is
decelerated at 2 m/s?. Justify will he be able to stop in time?
Answer: Yes
Explanation:
Given
Martin initial speed is [tex]u=20\ m/s[/tex]
Stones is at 170 m ahead
Deceleration [tex]a=2\ m/s^2[/tex]
Using the equation of motion [tex]v^2-u^2=2as[/tex]
Insert the values
[tex]0-20^2=2\times (-2)s\\s=\dfrac{400}{4}\\\\s=100\ m[/tex]
So, it took 100 m to stop completely. Hence martin will be able to stop in time.
Which action could a student take to produce a longitudinal wave with a large amplitude?
A. Drop a pebble in a pond.
B. Light a candle.
C. Bang on a drum.
D. Stand as still as possible.
Answer:
Bang on a drum.
Explanation:
Amplitude is making loud sounds
Find the height of the coconut from the ground at the moment the arrow hit it.
Answer:
[tex]v = u + at \\ 0 = 45 \sin(20) - 9.81 \times t \\ t = 1.56s[/tex]
An area experiences thunderstorms with high winds and a drop in temperature. Which weather event most likely occurred? A. A stationary front moved through the area. B. A fast-moving warm front moved trough the area. C a fast-moving cold front moved through the area. D. A slow-moving warm front followed a fast-moving cold front through the area
Answer:
C a fast-moving cold front moved through the area.
Explanation:
This is because, since there is a there is a thunderstorm and high winds in the area, this can only be caused by a fast moving front. Also there is a temperature drop, this can only be caused by the fast moving cold front since a cold front has a low temperature.
Thus, for the area to experience thunderstorms with high winds and a drop in temperature, a fast-moving cold front moved through the area.
Next, given the equivalent resistance,
Req(23), what is the equivalent
resistance, Reg, of the series
combination of R1 and Req(23)?
Ri
Req(23)
100 12
120 12
Answer:
Req= 220 ohm
Explanation:
In series combination just add the resistances.
Req=R1+Req(23)
Req=100+120
Req= 220 ohm
A person walking in high heals can damages the floor by making small dimples in the floor since all their weight is concentrated on the tip of the high heal. It the person weighs 81 kg and the high of the tip of the high heal is 3.5 cm2, what is the force over the floor?
Given :
Mass of person, m = 81 kg.
Area of high heal, A = 3.5 cm² = 0.00035 m².
To Find :
The pressure applied by the heal on the ground.
Solution :
We know, pressure is given by :
[tex]P = \dfrac{mass}{Area}\\\\P = \dfrac{81}{0.00035} \ N/m^2\\\\P = 231428.57 \ N/m^2[/tex]
Hence, this is the required solution.
Global heating trend on Earth, the atmosphere expands and the length of the day increases very slightly. Explain why the length of day increases
Answer:
Due to increase in the inertia and velocity of the earth by the warming of air.
Explanation:
Due to the rise of global warming, the effects of GHG gases are increasing and the atmosphere warms and starts to expand with the length of the day. This is due to the movement of the earth's expanding air cause the earth's inertia to increase which causes the mass to go or bulge outwards. The velocity increases with the movement of inertia and thus causes the day to lengthen.