Answer:
2:1
Explanation:
A compound wall consists of parallel layers of two different materials, 10 cm of brick and 2 cm of wood. If the difference of temperature across the brick wall is 20° C calculate the temperature difference between the wooden wall and heat current per square metre of the wall. [Thermal conductivity of brick and wood are respectively 0.5Wm-K- and 0.125Wm-'K']
The temperature difference between the wooden wall is 16⁰C, and the heat current per square metre of the wall is 7,325 W/m².
Temperature difference between the wooden wallThe temperature difference between the wooden wall is calculated as follows;
Let the brick wall = wall ALet the wooden wall = wall BLet the area of the walls = A[tex]\frac{dQ_A}{dt } = \frac{dQ_B}{dt} \\\\\frac{K_A \Delta T_A \times A}{L_A} = \frac{K_B \Delta T _B \times A}{L_B}\\\\\frac{K_A \Delta T_A }{L_A} = \frac{K_B \Delta T _B}{L_B}\\\\\frac{0.5 \times 20}{0.1} = \frac{0.125 \times \Delta T _B }{0.02} \\\\100 = 6.25\Delta T _B\\\\\Delta T _B = \frac{100}{6.25} \\\\\Delta T _B = 16 \ ^oC[/tex]
Heat flowing in the wallsQ = KL(ΔT)
Q = 0.5 x 0.1 x (20 + 273)
Q = 14.65 W
Heat current per square meter of the WallsQA = W/A
QA = (14.65)/A
Let the area of the wall = 10 cm x 2 cm = 0.1 m x 0.02 m = 0.002 m².QA = 14.65/0.002
QA = 7,325 W/m²
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is it possible to make your lifetime displacement zero, if so where would you go?
Answer:
Yes
Explanation:
Displacement is the distance from the starting point to the end point. If you live and die at the same place, you will have 0m as your displacement.
Two cities in the same climate zone must have the same climate and weather conditions. Why is this statement true or false?
A. It is false because cities in the same climate zone must have different climates.
B. It is false because the two cities might differ in their proximity to water.
C. It is true because the two cities are at the same latitude.
D. It is true because the two cities will be closer to the equator.
Answer:
C
Explanation:
true because c is the best answer
Answer: The answer is C. It is true because the two cities are at the same latitude.
Explanation:
Hi I was doing the same test are u in flvs lol I am too if you are!
A drum is struck, producing a wave with a wavelength of 110 cm and a speed of
2.42 × 104 m/s. What is the frequency of the wave? What is the period?
Explanation:
wavelength = l
speed of wave = v
frequency = f
v = lf → f = v/l = 2.42 × 10⁴ ÷ 1.1 = 2.2 × 10⁴ 1/s
T = 1/f = 1/ 2.2 × 10⁴ = 0.45 × 10 -⁴ s
The frequency of the sound wave produced from the drum is the speed divided by the wavelength. The frequency of the wave 22 kHz.
What is frequency ?Frequency of a wave is the number of wave cycles per unit time. Frequency of a wave is directly proportional to the energy and inversely proportional to the wavelength.
The relation between speed of the wave c, wavelength and frequency of the wave can be written as follows:
c = νλ.
Given speed of the sound wave produced from the drum = 2.42 × 10⁴ m/s
wavelength λ = 110 cm = 1.1 m
The frequency of the sound wave = speed/wavelength
ν = 2.42 × 10⁴ m/s / 1.1 m = 22000 Hz or 22 kHz.
Time period = 1/frequency
T = 1/ 22000 = 4.45× 10⁻⁵ seconds.
Therefore, the frequency of the wave is 22 kHz and time period of 4.45× 10⁻⁵ seconds.
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22. What is the length of a pendulum that has a period of 0.500 s?
Please show all of your steps to find the solution.
6.21 cm
use the pendulum formula : [tex]\sf \bold{\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{L}}{\mathrm{g}}}}[/tex]where
T is time or periodπ is pie = 22/7L is pendulum lengthg is acceleration due to gravityGiven:
T = 0.500 sg = 9.8 m/s²solving step-wise:
[tex]\dashrightarrow \mathrm{T}=2 \pi \sqrt{\dfrac{\mathrm{L}}{\mathrm{g}}}[/tex]
[tex]\sf \dashrightarrow \mathrm{0.5}=2 \pi \sqrt{\dfrac{\mathrm{L}}{\mathrm{9.8}}}[/tex]
[tex]\dashrightarrow \mathrm{\dfrac{0.5}{2 \pi } }=\sqrt{\dfrac{\mathrm{L}}{\mathrm{9.8}}}[/tex]
[tex]\dashrightarrow\sqrt{\dfrac{\mathrm{L}}{\mathrm{9.8}}}= \mathrm{\dfrac{0.5}{2 \pi } }[/tex]
[tex]\sf \dashrightarrow{\dfrac{\mathrm{L}}{\mathrm{9.8}}}= (\mathrm{\dfrac{0.5}{2 \pi } })^2[/tex]
[tex]\sf \dashrightarrow{{\mathrm{L}}= (\mathrm{\dfrac{0.5}{2 \pi } })^2*9.8[/tex]
[tex]\sf \dashrightarrow{{\mathrm{L}}=0.06205922 \ m[/tex]
1 m → 100 cm[tex]\sf \dashrightarrow{{\mathrm{L}}=6.2059\ cm[/tex]
[tex]\sf \dashrightarrow{{\mathrm{L}}=6.21\ cm[/tex] { rounded to nearest hundredth }
Let's see
[tex]\\ \rm\rightarrowtail T=2\pi \sqrt{\dfrac{l}{g}}[/tex]
[tex]\\ \rm\rightarrowtail 0.5=2\pi \sqrt{\dfrac{l}{9.8}}[/tex]
[tex]\\ \rm\rightarrowtail 0.783=\pi \sqrt{l}[/tex]
[tex]\\ \rm\rightarrowtail 0.2494=\sqrt{l}[/tex]
[tex]\\ \rm\rightarrowtail \ell=0.0622m[/tex]
If you were standing on the edge of a thunderstorm as it begins to form, would the wind be blowing into the storm or out of it? why?
You’ll start by investigating how earth’s surface temperature varies. open my nasa data, and click on data set in the top left corner of the page. within the atmosphere category, select all data, then select temperature. now, select monthly air surface temperatures. after the new map appears on your screen, select the animate option near the top of the page, and then select ok to see the animation. set the time range on the animation for the most recent five years, and then click submit. you can control the speed of the animation with the controls beneath the map.
question 1
describe patterns you observe in earth’s surface temperature. how do these patterns change during the course of a year and from year to year? use lines of latitude and degrees celsius in your description.
Different patterns we observe in earth’s surface temperature due to angle, distance from the sun, latitude of the place and ocean currents.
Describe patterns you observe in earth’s surface temperature?The Earth's surface experiences a range of temperature due to different conditions such as angle of the sun, distance from the sun, the latitude of the place, distance from the sea, altitude of the place and ocean currents.
So we can conclude that different patterns we observe in earth’s surface temperature due to angle, distance from the sun, latitude of the place and ocean currents.
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When a car is struck by lightning, the resulting electric field inside the car is.
Answer: When a car is struck by lightning, the resulting electric field inside the car is zero.
Explanation:
this one too!! need just 1 answer about this system
Answer:
A
Explanation:
The endocrine system has all of the body's hormones it regulates the biological processes. For example it can help brain development, nervous system development, and it can regulate blood sugar. (This is the closest to A)
1. manganese dioxide is used in dey cell . ( Give reason)
2. Fuses are used in a circuit. ( Give reason )
Answer:
1.In dry cells, manganese dioxide acts as a ‘depolariser'.
In the depolarization process, the depolariser is used to remove hydrogen and doesn't allow the voltage to get reduced due to polarisation of the cell . Manganese oxide was used as a depolariser in Leclanché cell .
In zinc-carbon dry cell, the manganese dioxide takes in electrons as it is converted to Manganese III oxide (Mn2O3)
2.The fuse breaks the circuit if a fault in an appliance causes too much current flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks the circuit.
Scientists predict that in another 250 million years, the continents will be located in different positions. How is this possible? *
Answer:
The continents will be in different positions because tectonic plate boundaries are always moving.
A weight of 200 n is hung from a spring with a spring constant of 2500 n/m and lowered slowly. How much will the spring stretch?
8n/m this is because 200×2500 all over 100 . 0's will cancile 0's living 200×2500×1 ,25 will go into 200 8 times ×1 =8n/m
The length by which the spring got stretched will be 0.08 m. The force is directly propotional to the distance by which the spring stretched.
What is spring force?The force required to extend or compress a spring by some distance scales linearly with respect to that distance is known as the spring force. Its formula is
F = kx
The given data in the problem is;
F is the spring force =200
K is the spring constant= 2500 N/m
x is the length by which spring got stretched =?
The stretch of the spring is found as;
[tex]\rm F=kx \\\\ x = \frac{F}{k} \\\\\ x= \frac{200}{2500} \\\\ x=0.08 \ m[/tex]
Hence the length by which the spring got stretched will be 0.08 m.
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The change in momentum that occurs when a 1. 0 kg ball traveling at 4. 0 m/s strikes a wall and bounces back at 2. 0 m/s is.
Answer:
The change is momentum is given by ∆p=p(inital) - p(final) =4-2=2 kg.m/s
Explanation:
momentum is the product of mass and velocity (speed)
So it's initial momentum would be:
p=mv=(1)(4)=4 kg.m/s
It's final momentum is given by:
p=mv=(1)(2)=2 kg.m/s
Is the following sentence true or false? When two surfaces rub, the irreg-ularities of one surface get caught on those of the other surface.
Does a photon emitted by a higher-wattage red light bulb have more energy than a photon emitted by a lower-wattage red bulb
Answer:
The energy of these two photons would be the same as long as their frequencies are the same (same color, assuming that the two bulbs emit at only one wavelength.)
Explanation:
The energy [tex]E[/tex] of a photon is proportional to its frequency [tex]f[/tex]. The constant of proportionality is Planck's Constant, [tex]h[/tex]. This proportionality is known as the Planck-Einstein Relation.
[tex]E = h\, f[/tex].
The color of a beam of visible light depends on the frequency of the light. Assume that the two bulbs in this question each emits light of only one frequency (rather than a mix of light of different frequencies and colors.) Let [tex]f_{1}[/tex] and [tex]f_{2}[/tex] denote the frequency of the light from each bulb.
If the color of the red light from the two bulbs is the same, those two bulbs must emit light at the same frequency: [tex]f_{1} = f_{2}[/tex].
Thus, by the Planck-Einstein Relation, the energy of a photon from each bulb would also be the same:
[tex]h\, f_{1} = h\, f_{2}[/tex].
Note that among these two bulbs, the brighter one appears brighter soley because it emits more photons per unit area in unit time. While the energy of each photon stays the same, the bulb releases more energy by emitting more of these photons.
Suppose that two point charges, each with a charge of 1 coulomb are separated by a distance of 1 meter. Determine the magnitude of the electrical force between them
The magnitude of the electrical force between the two identical electrical charges is 8.98755 × 10⁹N.
Given the data in the question;
Single charge each with; [tex]q_1\ and\ q_2[/tex] [tex]= 1C[/tex]Distance between; [tex]r = 1m[/tex]Electric force between; [tex]F = \ ?[/tex]Coulomb's lawCoulomb's law states "that the force between two electrical charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them".
It is expressed as;
[tex]F = k\frac{q_1q_2}{r^2}[/tex]
Here, [tex]q_1\ and\ q_2[/tex] are the two electrical charges, r is the distance between them and k is the Coulomb constant ( [tex]k = 8.98755*10^9 kgm^3/s^2C^2[/tex])
To determine the electrical force between the two charges, we substitute our values into the expression above.
[tex]F = k\frac{q_1q_2}{r^2}\\\\F = (8.98755*10^9 kgm^3/s^2C^2)*\frac{(1C)(1C)}{(1m)^2}\\\\F = (8.98755*10^9 kgm^3/s^2C^2)*\frac{1C^2}{1m^2}\\\\F = 8.98755*10^9 kgm/s^2\\\\F = 8.98755*10^9 N[/tex]
Therefore, the magnitude of the electrical force between the two identical electrical charges is 8.98755 × 10⁹N.
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The magnitude of the electrical force between the two charges is 8.987×10⁹ N.
What is coulomb's law?As per the coulomb's law, the electrical force between any two charges separated by a distance of r is given by the formula,
[tex]F = k\dfrac{q_1q_2}{r^2}[/tex]
Given that the value of q₁ and q₂ is 1 coulomb, while the distance between them is 1 meter. Also, the value of k is 8.987×10⁹ N·m²·C⁻², therefore, the force can be written as,
[tex]F = k\dfrac{q_1q_2}{r^2}\\\\F = (8.987 \times 10^{9}) \times (\dfrac{1 \times 1}{1^2})\\\\F= 8.987 \times 10^{9}\rm\ N[/tex]
Hence, the magnitude of the electrical force between the two charges is 8.987×10⁹ N.
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What is atmospheric pressure?
The value of gravitational pull on the moon is 1.6m/s/s. what is the weight of a 85kg astronaut on the moon?
weight=
mass=
gravity=
formula:
substitution:
answer:
Explanation:
Gravity = 1.6 m/s^2
Mass = 85 kg
Full infomation needed your question is incomplete and BTW fomula : G Mm
R^2
A car of mass 1200kg moving 90km/hr is brought to rest over a distance of 20m. calculate breaking force.
Answer:
-18,750N
Explanation:
90x1000
-------------
3600
u=25m/s
v=0m/s
v^2=u^2+2as
v=0
=625+(2×a×20)
625+40a
-625=40a
a= -15.625 m/s^2
F=ma
=(1200)(-15.625)
= -18,750N
1. A temperature unit is known as a
Explanation:
i think is per the International System of Units is Kelvin which is represented by the symbol K.
If a food has 200 calories and 7 grams of protein, and each gram of protein is 4 calories, what percent of the serving comes from protein?
Answer: 13%
Explanation: The reason this is 13 is because you can eat carlories and you can also be an amazing person 200 calories and 7 grams
13.
Jenny and her brother Tom sit on opposite ends of a seesaw. Jenny is
40 kg and her brother is 30 kg. If Jenny sits 1.5 meters from the pivot
point and Tom sits 1 meter from the pivot point, what is the net torque
on the seesaw?
The net torque on the seesaw is 294 Nm.
What is torque?Torque is the force that tends to rotate the body to which it was applied.
To calculate the net torque, we use the formula below
Formula:
τ = mgd-m'gd'........... Equation 1Where:
τ = Net torquem = Jenny's massm' = Tom's massd = Jenny's distance from the pivotd' = Tom's distance from the pivotg = acceleration due to gravityFrom the question,
Given:
m = 40 kgm' = 30 kgd = 1.5 md' = 1 mg = 9.8 m/s²Substitute these values into equation 1
τ = (40×1.5×9.8)-(30×1×9.8)τ = 588-294τ = 294 NmHence, The net torque on the seesaw is 294 Nm.
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Mass m1 on the frictionless table of the figure is connected by a string through a hole in the table to a hanging mass m2
For a mass m1 on the frictionless table, the speed m1 must rotate a with radius r if m2 is to remain hanging at rest is mathematically given as
[tex]v=\sqrt{m1/m2*xg}[/tex]
What speed must m1 rotate in a circle of radius r if m2 is to remain hanging at rest?Generally, the equation for the Force is mathematically given as
Fc=Fw
Therefore
[tex]\frac{m1v1}{x}=m2g[/tex]
[tex]v=\sqrt{m1/m2*xg}[/tex]
In conclusion, if m2 is to remain hanging at rest the speed of ratio of m1 is calcuylated using
[tex]v=\sqrt{m1/m2*xg}[/tex]
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The value of the velocity for the mass m₁ on the frictionless table will be [tex]\rm v = \sqrt{\frac{m_1}{m_2 xg} }[/tex]. Velocity is a time-based component. Its unit is m/sec.
What is velocity?The change of distance with respect to time is defined as speed. Speed is a scalar quantity.
The given data in the problem is
m is the mass
g is the acceleration of free fall =10m/sec²
v is the velocity
From the balancing equation of force the centripetal force is equal to the weight;
[tex]\rm F_c= m_2 g \\\\ \rm \frac{m_1v_1^2}{x} = m_2 g \\\\ v= \sqrt{\frac{m_1}{m_2xg} } \\\\[/tex]
Hence the value of the velocity for the mass m₁ on the frictionless table will be [tex]\rm v = \sqrt{\frac{m_1}{m_2 xg} }[/tex].
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25. How long does it take a child on a swing to complete one swing if her center of gravity is 4.00 m below the pivot?
Please include all of your steps with the solution.
[tex]\\ \rm\rightarrowtail T=2\pi\sqrt{\dfrac{l}{g}}[/tex]
[tex]\\ \rm\rightarrowtail T=2\pi\sqrt{\dfrac{4}{9.8}}[/tex]
[tex]\\ \rm\rightarrowtail T=2\pi(0.63887)[/tex]
[tex]\\ \rm\rightarrowtail T=1.27774\pi [/tex]
[tex]\\ \rm\rightarrowtail T=4.012s[/tex]
An apple weighing 1 N fall a distance of 1 m how much work is done on the Apple by the force of gravity
Explanation:
work = Force×distance
Force in this question is equal to the weight (force of gravity)
work = 1 × 1 = 1 J
Jole is the unit of work
The presence of which magnetic feature best explains why a magnet can act at a distance on other magnets or on objects containing certain metals? fields dipoles domains forces
The orientation with the largest magnetic torque on the dipole is Orientation B (See attached image).
What is Magnetic Torque?The torque on the dipole is defined as:
τ = µ×B,
where B is the external magnetic field.
The magnitude of this torque is µB sinθ, where θ is the angle between B and µ
Magnetic Torque is highest when;
→ →
µ ⊥ β
That is when θ = 90°. Hence B is the correct answer. Please see attached image.
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Answer:
b
Explanation:
Which red line shows the same action spectrum corrected for the unequal number of photons emitted across the visible spectrum?.
The visible spectrum is composed of red, orange,yellow, green, blue, violet, indigo.
What is visible spectrum?The visible spectrum refers to the portion of the electromagnetic spectrum that can be seen with the eyes. All other portions of the electromagnetic spectrum are invisible.
The question is incomplete as the details are missing. The visible spectrum is composed of red, orange,yellow, green, blue, violet, indigo.
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hey guys can y’all help quickly?
how to induce a positive temporary charge on the right side of a metal ball
Answer:
Temporary? You have two options
If you have a positively charged object, bring it close to the LEFT side of the ball (not touching it!).
If you have a negatively charged object, bring it close to the RIGHT side of the ball (again, not in contact).
Either way, the electron cloud will migrate towards the right side of the of your sphere.
Another option is to have a capacitor large enough to house the sphere inside it, and polarize it by attaching it to a DC source making sure that the negative plate of it is to the right of the sphere.
An object of mass 5kg falls from rest and has a kinetic energy of 1500J midway its journey.
a) what is its potential energy at this point?
b) what is the potential energy it started with?
c) what is it’s kinetic energy before hitting the ground?
Answer:
a) 1500 j
b) 3000 j
c) 34.64 m/s
Explanation:
at halfway point 1/2 of the potential energy has been converted to kinetic energy
so 1 /2 P E = 1500 j
it will still have the OTHER half of its PE 1500 j
c) PE will be entirely converted to KE when it is at the bottom
KE = 1/2 m v^2
3000 = 1/2 (5)(v^2) show v = 34.64 m/s
Can you hear the vibrations a tuning fork puts off when hit?
no
Explanation:
no not an vibration signal