Answer:
1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;
i) The cost of manufacture of nichrome is low
ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting
iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element
iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater
v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied
2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level
Explanation:
(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg.
Complete question:
(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C
Answer:
The energy that must be supplied to boil the given mass of the water is 672,000 J
Explanation:
Given;
mass of water, m = 2 kg
heat of vaporization of water, L = 330 kJ/kg
initial temperature of water, t = 20 ⁰C
specific heat capacity of water, c = 4200 J/kg⁰C
Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;
Q = mc(100 - 20)
Q = 2 x 4200 x (80)
Q = 672,000 J
Q = 672,000 J
Q = 672,000 J
Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J
Pls help it’s really late <3
Answer:
22.4%
Explanation:
The plane is 300000 kg
It is 11000 meters about the earth's surface.
g = 9.81
PE = mgh
PE = 300000 * 9.81 * 11000
PE = 3.24* 10^10
The Kinetic Energy
KE = 1/2 m * v^2
m = 300000
v = 250 m/s
KE = 1/2 300000 * (250 m/s)^2
KE = 9.375 * 10^9
Total Energy = 3.24 * 10^10 + 9.375 * 10^9
Total Energy = 4.17 * 10^10
9.375 * 10^9
=========== * 100 % = 22.44 %
4.17 * 10^10
describe the application of Pascal's law in hydraulic excavator.
plz help me
Explanation:
The hydraulic system works on the principle of Pascal's law which says that the pressure in an enclosed fluid is uniform in all the directions. ... As the pressure is same in all the direction, the smaller piston feels a smaller force and a large piston feels a large force.
The wind blows a leaf at 37.9 m/s for 118 s left. How are does the leaf go in that period of time.
A) 3.11 m, left
B) 4470 m, left
C) 80.1 m, left
D) 0.321 m, left
Explanation:
distance = velocity * time
d = 37.9 * 118
distance = 4472.2
10 points
Calculate the force of attraction between the moon and the earth, if their masses and distance apart are 10^22Kg, 10^24kg and 6.4x10^6m. Take g = 6.67x10^-11Nm^2Kg^-2
a) 0.63x10^24N
b) 1.63x10^22N
c) 2.63x10^20N
d) 3.63x10^18N
Answer:
Explanation:
You didn't fill in the proper masses which is why you never got an answer to this. But that's ok...I got you. I happen to know what they are! We will use the universal law of gravitation and the gravitational constant to solve this.
[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] and filling in:
[tex]F_g=\frac{(6.67*10^{-11})(5.98*10^{24})(7.36*10^{22})}{(3.84*10^8)^2}[/tex] The denominator is the radius of the earth plus the radius of the moon plus the distance between their surfaces, just FYI.
That gives us that
[tex]F_g=1.99*10^{20}N[/tex] Not sure what your choices entail, but I'd have to say, taking into consideration that maybe your problem didn't figure in the distance between the surfaces, you'd be at choice B.
1. A 14-cm tall object is placed 26 cm from a converging lens that has a focal length of 13 cm.
Answer:
a) Please find attached the required drawing of light passing through the lens
By the use of similar triangles;
The image distance from the lens = 26 cm
The height of the image = 14 cm
c) The image distance from the lens = 26 cm
The height of the image = 14 cm
Explanation:
Question;
a) Determine the image distance and the height of the image
b) Calculate the image position and height
The given parameters are;
The height of the object, h = 14 cm
The distance of the object from the mirror, u = 26 cm
The focal length of the mirror, f = 13 cm
The location of the object = 2 × The focal length
Therefore, given that the center of curvature ≈ 2 × The focal length, we have;
The location of the object ≈ The center of curvature of the lens
The diagram of the object, lens and image created with MS Visio is attached
From the diagram, it can be observed, using similar triangles, that the image distance from the lens = The object distance from the lens = 26 m
The height of the image = The height of the object - 14 cm
b) The lens equation is used for finding the image distance from the lens as follows;
[tex]\dfrac{1}{u} + \dfrac{1}{v} = \dfrac{1}{f}[/tex]
Where;
v = The image distance from the lens
We get;
[tex]v = \dfrac{u \times f}{u - f}[/tex]
Therefore;
[tex]v = \dfrac{26 \times 13}{26 - 13} = \dfrac{26 \times 13}{13} = 26[/tex]
The distance of the image from the lens, v = 26 cm
The magnification, M =v/u
∴ M = 26/26 = 1, therefore, the object and the image are the same size
Therefore;
The height of the image = The height of the object = 14 cm.
What variable is represented with the letter V?
a. Velocity
b. Vector
c. Acceleration
d. Displacement
Answer:
a.VelocityExplanation:
#Hope it helpsAnswer:
A
Explanation:
find the magnitude and angle of a vector given the components: Bx=7, By=-5
Answer:
Magnitude = 8.6
Angle = 324.5 degree from + X axis in counter clock wise direction.
Explanation:
X component of B, Bx = 7
Y component of B, By = - 5
The magnitude of the resultant is
[tex]B =\sqrt{7^{2}+(-5)^2}\\\\B =\sqrt{49+ 25}\\\\B = 8.6[/tex]
The angle is given by
[tex]tan\theta=\frac{By}{Bx}\\\\tan\theta = \frac {-5}{7}\\\\\theta = 324.5^{o}[/tex]
Examine the following output:
4 22 ms 21 ms 22 ms sttlwa01gr02.bb.ispxy.com [154.11.10.62]
5 39 ms 39 ms 65 ms plalca01gr00.bb.ispxy.com [154.11.12.11]
6 39 ms 39 ms 39 ms Rwest.plalca01gr00.bb.ispxy.com [154.11.3.14]
7 40 ms 39 ms 46 ms svl-core-03.inet.ispxy.net [205.171.205.29] 8 75 ms 117 ms 63 ms dia-core-01.inet.ispxy.net [205.171.142.1] Which of these commands produced this output?
A. tracert
B. nslookup
C. pingroute
D. ping
Answer:
A. tracert
Explanation:
Tracert is a computer diagnostic command which displays possible routes for delays in packets of Internet Protocol (IP). Tracert command will display results for route which is recorded round trip times of packet.
define the term capacitance and its SI unit
Answer:
See explanation below
Explanation:
Capacitance is the amount of electric charge stored on a conductor and its SI unit is Farads (F).
Answer:
capacitance is the amount electric charges of a conductor, its si is farads
Bye , :-)
A hydrometer is an instrument used to determine liquid density. A simple one is sketched in the figure below. The bulb of a syringe is squeezed and released to lift a sample of the liquid of interest into a tube containing a calibrated rod of known density. (Assume the rod is cylindrical.) The rod, of length L and average density 0, floats partially immersed in the liquid of density . A length h of the rod protrudes above the surface of the liquid. Show that the density of the liquid is given by
=
0L
L − h
.
(Do this on paper. Your instructor may ask you to turn in this work.)
Answer:
weight of rod =weight of liquid displaced
mass of the rod ×g =mass of liquid displaced ×g
(g cancelled out)
mass of the rod =mass of liquid displaced
density of rod ×volume of rod =density of liqiud ×volume of liquid displaced
O×cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface
O×L=density of liquid ×(L-h)
then density of liquid =OL/(L-h) shown as required
The density of the liquid is given by =OL/L − h
What is density?Density is the ratio of mass of an object and its volume.
According to the Archimedes principle, weight of rod = weight of liquid displaced
mass of the rod ×g =mass of liquid displaced ×g
So, mass of the rod =mass of liquid displaced
Mass in terms of density is substituted,
density of rod × volume of rod =density of liquid ×volume of liquid displaced
O× cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface
O×L=density of liquid ×(L-h)
Then, density of liquid =OL/(L-h).
Learn more about density.
https://brainly.com/question/9215083
#SPJ2
please help me with this question.... thank u ❤️
Answer:
20 degrees
Explanation:
Because projectile has the same range on both angles which on summation gives 90 degrees as a total.
You hear the dishwasher with a loudness of 40 dB and a siren outside
with a loudness of 60 dB. How much greater is the amplitude of the
siren's sound than the amplitude of the dishwasher's sound?
Answer:
The ratio of the amplitudes of siren to dishwasher is 10.
Explanation:
loudness of dishwasher = 40 dB
loudness of siren = 60 dB
let the intensity of dishwasher is I an the intensity of siren is I'.
Use the formula of intensity and decibels.
[tex]dB = 10 log\frac{I}{I_o}\\\\40=10 log\frac{I}{I_o}\\\\4 = log\frac{I}{I_o}\\\\I = 10000 I_o[/tex]
And
[tex]60=10 log\frac{I'}{I_o}\\\\60 = log\frac{I'}{I_o}\\\\I' = 1000000 I_o[/tex]
The intensity if proportional to the amplitude.
[tex]\frac{A'}{A}=\sqrt\frac{1000000}{10000}\\\\\frac{A'}{A}= 10[/tex]
PLSSSSS HELPPPPP
Consider the potential energy diagram shown below. This graph shows the chemical potential energy in a reaction system over time. The y-axis is potential energy in kilojoules. The x-axis is the reaction progress, or time.
The far left part of the curve is horizontal and has an energy value of 50 kJ. The curve then rises to a peak of 250 kJ before falling to a horizontal region at 200 kJ.
Does this graph represent an endothermic or an exothermic reaction? Explain your answer.
What is the enthalpy change, ΔH, for this reaction? Show your work.
What is the activation energy, Ea, for this reaction? Show your work.
In a particular chemical reaction, the energy of the reactants is 30 kJ and the energy of the products is 5 kJ. The maximum energy of the system is 40 kJ.
Sketch a potential energy diagram for this reaction. Make sure to label the energy of the reactants, the energy of the products, the activation energy, and the enthalpy change for the reaction.
What is the activation energy for this reaction?
What is the enthalpy change for this reaction?
Is this reaction endothermic or exothermic? Explain your answer in two ways: first, using the energy values, and second, by referring to the shape of the graph.
The coating on the head of a match is highly flammable. When it burns, it releases a great deal of energy. However, before the match can burn, it must gain a small amount of energy from a spark. That spark is typically produced by striking (rubbing) the match head against a rough surface. Sketch and describe a potential energy diagram that represents the striking and burning of the match. Remember to label the diagram with the energy changes that occur. Your answer must include the potential energy diagram and a written description. (Note: you do not have to use actual energy values.)
Answer:
A. Endothermic reaction.
B. +150KJ.
C. 250KJ.
Explanation:
A. The graph represents endothermic reaction because the heat of the product is higher than the heat of the reactant.
B. Determination of the enthalpy change, ΔH for the reaction. This can be obtained as follow:
Heat of reactant (Hr) = 50KJ
Heat of product (Hp) = 200KJ
Enthalphy change (ΔH) =..?
Enthalphy change = Heat of product – Heat of reactant.
ΔH = Hp – Hr
ΔH = 200 – 50
ΔH = +150KJ
Therefore, the enthalphy change for the reaction is +150KJ
C. The activation energy for the reaction is the energy at the peak of the diagram.
From the diagram, the activation energy is 250KJ.
Do only number 2 and thank
Answer:
Quantity of charge = 0.8 Coulombs
Explanation:
Given the following data;
Current = 0.4 A
Time = 2 seconds
To find the quantity of electricity transferred;
Mathematically, the quantity of electricity (charge) passing through a conductor is given by the formula;
Quantity of charge = current * time
Substituting into the formula, we have;
Quantity of charge = 0.4 * 2
Quantity of charge = 0.8 Coulombs
When should a bar graph be used?
A. When the independent variable is composed of categories and does not show a
relationship
B. When the independent variable is continuous and does not show a relationship to the
dependent variable.
C. When the independent variable is continuous and shows a causal link to the
dependent variable,
D. When there is no independent variable.
Answer:
B. When the independent variable composed of categories and does not show a relationship to the dependent variable
Explanation:
A bar graph, is a graph used for presenting data grouped into categories, which are the independent variables of the graph, and the measurement of each category, which are represented as rectangular bars having lengths proportional to the value of the category, on a chart
In the bar graph or chart, there is no direct relationship between the categories, which are the x-values and the dependent variables , which are the length of the bars, the y-values, as the length of the rectangular bar in one category, cannot be obtained from another category through a relationship
Therefore, the correct option is option is when the independent variable composed of categories and does not show a relationship to the dependent variable
Which statement about the mass and the weight of an object is correct?
A They are both affected by changes in the acceleration of free fall.
B They are both forces.
C They have different units.
D Weight is calculated by dividing mass by the acceleration of free fall.
Answer:
HOPE IT HEPLED U !!!!
Explanation:
i think it's (C) They have different units ....
A cell supplies current of 0.6A and 0.2A through 1ohms and 4.0ohms resistor respectively. Calculate the internal resistance of the cell
0.5Ω
Explanation:Since different currents are passing through the resistors, then the resistors are most probably connected in parallel. This also means that the same voltage will pass across them.
Using Ohm's law, the voltage across a resistor in a circuit is given by;
V = I(R + r) -----------(i)
For the 1ohm resistor, the voltage across it is given by;
Where;
I = current passing through the 1 ohm resistor = 0.6A
R = resistance of the 1 ohm resistor = 1Ω
r = internal resistance of the cell = r
Substitute these values into equation (i) as follows;
V = 0.6(1 + r) -------------------(ii)
For the 4.0ohm resistor, the voltage across it is given by;
Where;
I = current passing through the 4.0 ohms resistor = 0.2A
R = resistance of the 4.0 ohms resistor = 4.0Ω
r = internal resistance of the cell = r
Substitute these values into equation (i) as follows;
V = 0.2(4.0 + r) -------------------(iii)
Now solve equations (ii) and (iii) simultaneously;
V = 0.6(1 + r)
V = 0.2(4.0 + r)
Substitute the value of V in equation (ii) into equation (iii). Therefore, we have;
0.6(1 + r) = 0.2(4.0 + r)
Solve for r
0.6 + 0.6r = 0.8 + 0.2r
0.6r - 0.2r = 0.8 - 0.6
0.4r = 0.2
r = [tex]\frac{0.2}{0.4}[/tex]
r = 0.5
Therefore, the internal resistance of the cell is 0.5Ω
negative acceleration is also known as
Answer:
Deceleration
Explanation:
The amount by which a speed or velocity decreases
Answer:
Negative Acceleration is called Deceleration.
Can someone explain to me why Ohms law stops working when the temperature of the component increases?
Answer:
Ohm's law verifies that current directly varies with voltage, when resistance increases, current current decreases.
When temperature increases, the electrons gain more average kinetic energy increases and current increases as well.
In the same situation, resistance also increases because atoms of a component vibrate at higher amplitudes about their mean positions hence reducing the free path of electrons. This increases resistance, hence ohms law violated or disobeyed.
This generates the temperature coefficient of resistance
100 J OF HEAT IS PRODUCED EACH SECOND IN A 4 COULUMB RESISTER. THE POTENTIAL DIFFERANCE ACROSS THE RESISTER WILL BE
Answer:
The correct answer is "20 Volts".
Explanation:
Given:
Heat,
H = 100 J
Resistance,
R = 4 Ω
As we know,
⇒ [tex]P=\frac{v^2}{R}[/tex]
By putting the values, we get
⇒ [tex]100=\frac{v^2}{4}[/tex]
⇒ [tex]v^2=100\times 4[/tex]
⇒ [tex]=400[/tex]
⇒ [tex]v=\sqrt{400}[/tex]
⇒ [tex]=20 \ volts[/tex]
Uas partículas com cargas = +1,0 e = +2,0 estão posicionadas conforme indica a figura. Determine o módulo do campo eléctrico resultante no ponto P, em N/C.
Martha is telling her teacher how an animal cell is like a house. Which part of an animal cell is like the doors and windows in Marthas house
Answer:
cell membrane.
Explanation:
A cell can be defined as the fundamental or basic functional, structural and smallest unit of life for all living organisms. Some living organisms are unicellular while others are multicellular in nature.
A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells.
Generally, cells have the ability to independently replicate themselves. In a cell, the "workers" that perform various functions or tasks for the survival of the living organism are referred to as organelles. Some examples of cell organelles found in all living organisms such as trees, birds, and bacteria include; nucleus, cytoplasm, cell membrane, golgi apparatus, mitochondria, lysosomes, ribosomes, chromosomes, endoplasmic reticulum, vesicles, etc.
Cell membrane is the wall of a cell in living organisms and it typically functions as a door and window in a house by controlling what leaves and enters the cell at any given time. Also, the cell membrane opens selectively and as such it would only open at certain times and to certain chemical changes or signals.
This ultimately implies that, the part of an animal cell that is like the doors and windows in Martha's house is the cell membrane.
Answer:
give the guy above brainlist
he did a very good job.
Explanation:
What produces magnetic fields?
Answer:
flowers
Explanation:
i'm really not sure but i have this gut feeling its flowers
My buddy and I are planning a shore dive. we're descending onto a very gradual slope that begins at 5 m/15 ft, so our descent and ascent will be a gradual part of swimming out and back underwater. we have similar cylinders filled to 2000 bar/3000 psi. We plan:
- 50 bar/500 psi reserve
- 20 bar/300 psi for our safety stop
- to turn the dive when we've used 1/3 of the air available to use on the dive
This means we should head back when either of our SPGs read
A. 70 bar/800 psi
B. 145 bar/1900 psi
C. 157 bar/2270 psi
D. 170 bar/2500 psi
Answer:
C. 157 bar/2270 psi
Explanation:
Calculation to determine what we should head back when either of our SPGs read
SPGs=200 bar -[200 bar-(50 bar + 20 bar)]÷1/3]
SPGs=200 bar-[(200 bar-70 bar)÷1/3]
SPGs=200 bar-(130 bar÷1/3)
SPGs=200 bar-43 bar
SPGs=157 bar/2270 psi
Therefore based on the above calculation we should head back when either of our SPGs read 157 bar/2270 psi
How much current is drawn by a computer with a resistance of 42Ω that is connected across a potential difference of 220 V?
9200 amps
6.6 amps
7.0 amps
5.2 amps
Answer:
5.2 amps
Explanation:
V = I*R
I = V/R
I = 220/42
I = 5.2 amps
Answer:
5.2
Explanation:
because
[tex]i \frac{v}{r} [/tex]
220÷42=5.23
can someone please help
The answer is B. Mono and polyunsaturated fats because the other two are really harmful and they are not healthy whatsoever.
A cyclist goes around a circular track once every 2 minutes. If the radius of the circular track is 110m,calculate the speed of the cyclist.
Answer:
5.76 m/s
Explanation:
Applying,
S = d/t............... Equation 1
Where S = speed, d = distance, t = time.
For circular motion,
d = 2πr............ Equation 2
Where r = radius of the circular track, π = pie
Substitute equation 2 into equation 1
S = 2πr/t.............. Equation 3
From the question,
Given: r = 110 m, t = 2 minutes = (2×60) = 120 s
Constant: π = 3.14
Substitute these values into equation 3
S = (2×3.14×110/120)
S = 690.8/120
S = 5.76 m/s
300kg of water are lifted 10m vertically in 5s show the work done in 30kj and that power is 6kw . Please help me
Answer:
6KW
Explanation:
The computation is shown below:
We know that
Work done= m ×g× h
Here
W= 300×10×10
= 30000 J
= 30 KJ
And
Power= Work done ÷time taken
P = 30000 ÷ 5
= 6000W
= 6KW
The above represent the answer
The motor of a boat develops 48 kW when the boat's speed is 12 km/h. With how much force does the water resist the motion of the boat?