Answer:
When you put un-like poles together (South facing North) you can feel magnetic attraction. In the Northern Hemisphere, your compass needle points North, but if you think about it for a moment, you will discover that the magnetic pole in the Earth's Northern Hemisphere has to be a South polarity.
Consider two walls, A and B, with the same surface areas and the same temperature drops across their thicknesses. The ratio of their thermal conductivities is kA/kB=4 and the ratio of the wall thickness is LA/LB=2. The ratio of heat transfer rates through the walls qA/qB is:
(a) 0.5
(b) 1
(c) 2
(d) 4
(e) 8
(f) None of them
Answer:
(c) 2
Explanation:
Heat transfer across the walls due to conduction is given by:
[tex]q = -KA\frac{\Delta T}{L}[/tex]
where,
q = heat transfer rate
K = thermal conductivity
A = Area
ΔT = change in temperature
L = thickness
For wall A:
[tex]q_A = -K_AA\frac{\Delta T}{L_A}[/tex]
For wall B:
[tex]q_B = -K_BA\frac{\Delta T}{L_B}[/tex]
Because the change of temperature and area of walls are the same. Dividing both terms:
[tex]\frac{q_A}{q_B} = \frac{\frac{K_A}{L_A} }{\frac{K_B}{L_B}}\\\\ \frac{q_A}{q_B} =\frac{\frac{K_A}{K_B} }{\frac{L_A}{L_B}}[/tex]
using values given in the question:
[tex]\frac{q_A}{q_B} = \frac{4}{2}\\\\\frac{q_A}{q_B} = 2[/tex]
Therefore, the correct answer is:
(c) 2
Why is your weight the same any place on Earth?
Answer: A person can weigh differently at various place on Earth because of the fluctuations in Earth's gravity, according to a new high-resolution map. ... Earth's gravity is weaker at the equator due to centrifugal forces produced by the planet's rotation
Explanation:
A 31 kg child is traveling at 4 m/s while sledding down a hill. What is the child's kinetic energy at the bottom of the hill?
Answer:
K.E = 248 J
Explanation:
Since the child is travelling at a given velocity. The kinetic energy of the child down the hill can be given by the following formula:
[tex]K.E = \frac{1}{2}mv^2\\[/tex]
where,
m = mass of the child = 31 kg
v = velocity of the child = 4 m/s
Therefore,
[tex]K.E = \frac{1}{2}(31\ kg)(4\ m/s)^2\\[/tex]
K.E = 248 J
In the nucleus ______________
tell cells what to do and how to change.
Answer:
i believe it is dna
Explanation:
if i remember correctly if the dna tells the cell what to do and how to do it
What are the most essential skills in Team Handball and why?
Answer:
The most important skill in handball is passing or throwing
Explanation:
You need to be able to pass the ball with accuracy. Throwing and shooting drills are normally incorporated into every training session for handball.
Answer:
Explanation:
The most important skill in handball is passing or throwing. You need to be able to pass the ball with accuracy. Throwing and shooting drills are normally incorporated into every training session for handball.
A rocket experiences a 45,000 N force as it accelerates at 30 m/s/s. What is the mass of the rocket?
Answer:
15,00kg
Explanation:
here's your solution
=> force = 45,000N
=> acceleration = 30m/s^2
=> mass = ?
=> Mass = force/acceleration
=> mass = 45,000/30
=> mass = 15,00kg
hope it helps
Radiation present in the environment but not produced by humans is called ______.
Answer:
background
Explanation:
HELP!!! 50 POINTS
4. Predicting What would have happened, in terms of thermal energy transfer, if the water temperature had originally been10.0°C? Explain your reasoning.
Context:Background InformationThe quantity of energy transferred by heat from a body depends on anumber of physical properties of the body and its surroundings. For a given substance, the rate at which thermal energy is transferred by conduction depends on temperature difference, cross-sectional area,and a thermal conductivity constant that is unique to the substance.By choosing one of these properties as a manipulated variable and making the other properties controlled variables, the effect of the manipulated variable on thermal conduction can be determined experimentally.In this investigation, you will study the rates of cooling of three containers of water of equal volume but different surface area.
Answer:
do u have a picture of the question?
Explanation:
it would be easier to solve
Which of the following is an example of potential energy?
A. The plant sitting on the desk
B. The airplane Flying in the air
C. The car driving on the Street
D. The person standing up
Answer:
A
Explanation:
potential energy is energy due to position
Label the parts of the wave.
Answer:
A: Wavelength
B: Crest
C: Trough
D: Amplitude
Answer:
A:
✔ crest
B:
✔ amplitude
C:
✔ trough
D:
✔ wavelength
Explanation:
7
Select the correct location on the image.
Objects A and B are brought close to each other. Object A will soon become positively charged. Identify the charge that must transfer for this
situation to occur.
+
A
B
Answer:
Explanation:
For A to become positively charged, a + charge must transfer from B to A.
The charge that must transfer for object A to become positively charged is the negative charge in object A.
What is charging by conduction?Charging by conduction occurs when a charged object causes the flow of electron when it comes in contact with an uncharged object.
An object can either be negatively or positively charged. An object is said to be positively charged when it contains more protons than electron.
Therefore, for object A to be positively charged, the charge that must transfer for object A to become positively charged is the negative charge.
Learn more about positive charge here:
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the molecules in a solid state have _______ energy then molecules in a gas state
Answer:
less
Explanation:
hope this helps....................:)
PLS HELP, WILL GIVE BRAINLIEST
Answer:
B. x = 50, Y = 100 ,Z= 150
sorry if it's wrong
what type of wave travels through matter only??
A mechanical wave can only travel through matter.
3/8 of light initial intensity is absorbed in the breaker with length of 2cm filled with 9% solution. Find the length of the beaker should be used to get transmittance 1/3 for the same solution
Answer:
Assume I1 = Io * T1 transmission proportional to thickness
I2 = Io * T2 I is intensity of light absorbed (3/8 absorbed)
I1 / I2 = T1 / T2
T2 = T1 * (I2 / I1) = 2 * (2/3 / 3/8) = 2 * 16/9 = 32/9 thickness for 2/3 absorbed
The length of the beaker when the transmittance is changed to one-third is 13.78 cm.
The given parameters;
length of the beaker when 3/8 of the light intensity is absorbed = 2 cm = 0.02 mTo find:
the length of the beaker when there is 1/3 transmittanceThe length of the beaker is calculated by applying Beer-Lambert law;
[tex]\frac{I}{I_o} = e^{-cl}[/tex]
[tex]\frac{I_1}{I_0} = e^{-cl_1} = \frac{3}{8} \ ----(1)\\\\\frac{I_2}{I_0} = e^{-cl_2}= \frac{1}{3} \ ---- (2)[/tex]
divide equation (1) by equation (2);
[tex]\frac{e^{-cl_1}}{e^{-cl_2}} = \frac{3}{8} \times \frac{3}{1} \\\\ (c \ is \ constant \ for \ both) \\\\e^{-l_1 + l_2} = \frac{9}{8} \\\\l_2 - l_1 = ln(\frac{9}{8} )\\\\l_2 - 0.02 = 0.1178\\\\l_2 = 0.1178 + 0.02\\\\l_2 = 0.1378 \ m\\\\l_2 = 13.78 \ cm[/tex]
Thus, the length of the beaker when the transmittance is changed to one-third is 13.78 cm.
Learn more here: https://brainly.com/question/2506921
Please help will mark brainliest
Why is the melting of ice a physical change?
A.
It changes the chemical composition of water.
B.
It does not change the chemical composition of water.
C.
It creates new chemical bonds.
D.
It forms new products.
E.
It is an irreversible change that forms new products.
Answer:
b
Explanation:
it melts yes but it's still water [same element] so there fore it's a physical change
Answer:
It does not change the chemical composition of water. Explanation: A physical reaction is defined as the reaction in which a change in shape, size takes place. No new substance gets formed in these reactions.
Explanation:
Hope this helped
Se deja caer una piedra en un pozo y al cabo de 10s se oye el choque contra el fondo si la velocidad de sonido es de 330 m/s. ¿ Cuál es la profundidad del pozo?
Translate : Physically, a stone is dropped into a well and after 10 seconds you can hear the crash against the bottom, if the speed?
Answer : 383 m
Caso #1 Leo Messi está jugando la final de la Champion league 2019-2020 y va a cobrar un tiro libre importante, necesita aplicar un análisis para poder alcanzar su objetivo que es acertar el gol. Responder
Answer:
Tiene que patear el balón cerca del nivel del suelo para conseguir el gol.
Explicación:
Leo Messi necesita patear el balón no en el aire, en el nivel del suelo para poder meter el gol para el equipo. Delante del fútbol hay muchos jugadores del equipo contrario dispuestos a detener el tiro libre de Leo Messi. Cuando Leo Messi patea el balón en el aire, los jugadores también saltan en el aire para detener el tiro libre que atraviesa la cabeza y para conseguir el gol Leo Messi tiene que evitar patear el balón en el aire y patear el balón cerca del nivel del suelo. que puede atravesar a los jugadores oponentes cuando lo saltan para detener el balón a través de sus cabezas para que el balón pase por debajo de sus pies y llegue a la portería.
verify the law of moment.
Explanation:
TO VERIFY THE PRINCIPLE OF MOMENTS WHICH STATES THAT IF A NUMBER OF COPLANAR FORCES ACTIING ON A BODY S ,KEEP IT IN EQUILIBRIUM AND THEIR MOMENT ARE TAKEN ABOUT ANY POINT IN THEIR PLANE,THE SUM OF THE CLOCKWISE MOMENTS ,IS EQUAL TO SUM OF ANTICLOCKWISE MOMENT.
please mark me brainlist :)Answer:
TO VERIFY THE PRINCIPLE OF MOMENTS WHICH STATES THAT IF A NUMBER OF COPLANAR FORCES ACTING ON A BODY, KEEP IT IN EQUILIBRIUM AND THEIR MOMENT ARE TAKEN ABOUT ANY POINT IN THEIR PLANE, THE SUM OF THE CLOCKWISE MOMENTS, IS EQUAL TO SUM OF ANTICLOCKWISE MOMENT.
Write a one paragraph essay about the importance of the different biomolecules in our life.
Answer:
#tried my bestt
do mark me as brainlist
Biomolecules are made by living organisms and they are made because they are functional. Biomolecules, or at least most of them, do not exist outside of living organisms because they are too complex to be created by chance chemical collisions. The odds of a single average sized protein to form by chance has been calculated at 1 out 10 to the 77th power. Biomolecules REQUIRE intelligent agency to form them.
The four main purposes of biomolecules are:
1. Structure (some proteins)
2. Energy storage and release (carbohydrates)
3. Protective layers (lipids)
4. Information storage and communication (DNA, RNA, endocrines of numerous various types and manipulated molecules, such as fatty acids)
physical sciences Practical test
so ummmm what about ?
because I cant see any actual question?
Calculate the distance of the end of a valley bearing in mind that the echo takes 0.7 seconds to be heard from the moment when the sound was produced.a
Answer:238m
Explanation:Distance = speed x time
Speed = 340 m/s
340 m/s x .07 s = 238m
1. An elevator is moving up at a constant velocity of 2.5 m/s, as illustrated in the
diagram below: The passenger has a mass of 85 kg,
a. Construct a force diagram for the passenger
a hole in a copper plate has a diameter of 1.325 cm at 21C°. At what tempreture is the diameter equal to 1.164 cm
Answer:14C
Explanation:
What is the relationship between the density of a substance and the speed of sound through that substance?
Answer:The greater the density of a medium, the slower the speed of sound. This observation is analogous to the fact that the frequency of a simple harmonic motion is inversely proportional to m, the mass of the oscillating object. The speed of sound in air is low, because air is easily compressible.
Explanation:
If an object has a mass of 15 kg and has a weight of 30 N, on some remote
planet, what would be the acceleration due to gravity on that planet?
HELP ME PLSSS What are the possible genotypes
of the F, offspring? What are the
possible phenotypes of the F,
offspring?
Answer:
the answer is b i think
Answer:Within an individual organism, the specific combination of alleles for a gene is known as the genotype of the organism, and (as mentioned above) the physical trait associated with that genotype is called the phenotype of the organism.
Explanation:
The phenotype is the trait those genes express. ... Looking at the possible offspring, each box (or possible offspring) has two copies of the dominant gene. This means there is a 100% chance of the offspring having brown eyes, or being BB. It's important to note here that each box represents a possible offspring.
who plays rob.lox , adopt me here?
Want to be friends?
pls answer this right I will give you a brainiest.
Answer:
i would pick c
Explanation:
because, w and y it is very bright and bright can be very conductive like it said.
A DC generator is the same as a(n)
A. electric motor.
B. AC generator.
C. armature.
D. electric current.
Answer:
A DC generator is the same as a(n)
C. armature