Jess wants to make her house more energy efficient. Insulating her loft, which will cost £460 and save £25 per year, is better long-term option. Therefore, option B is correct.
What is energy ?In order to accomplish work and to produce heat and light, energy must be transferred to a body or to a physical system. Energy is the quantitative attribute that does this. Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed.
Computers, vehicles, communications, state-of-the-art medical technology, and many other things are all powered by energy. The demand for dependable and economical energy is especially pressing for emerging countries. It may enhance things or perhaps save lives.
A turbine generator set transforms mechanical energy into electrical energy to produce electricity. Natural gas, coal, nuclear fission, biomass, petroleum, geothermal, and solar thermal are examples of energy sources where the heat generated is used to produce steam.
Thus, option B is correct.
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Maggie is a member of her school’s environmental club and is interested in recycling. She asks the question, “How does exposure to the environment affect recyclable plastics?”
What best describes why and how Maggie should change her question to make it a better scientific question?
The answer to the question leads to a testable hypothesis, so the question should be changed to prevent testing.
The question involves giving an opinion about recycling, so it should be changed to rely only on facts.
The focus of the question is too broad, so it should be narrowed to a single environmental factor.
The results are too uncertain, so the question should be changed to one that has a known outcome.
Answer:
C
Explanation:
Environmental factors provides ambiguity a particular one could be studied to see how it affects recyclable plastics.
A squeeze bottle squeezes when pressed. It regains its shape when pressed .It regains its shape when the pressure from your hand is withdrawn. What may happen if the squeeze bottle is pressed to take the sauce out and then immediately corked tightly? Will it regain its shape? If not, Why?
Answer:
The squeeze will not regain its shape
Explanation:
The squeeze bottle will not regain its shape.
This is because the atmospheric pressure compresses the squeeze bottle. Since the pressure in the squeeze bottle is now not equal to the atmospheric pressure since it has been corked tightly, its internal pressure cannot balance out the atmospheric pressure and thus cancel its effect.
So, the squeeze bottle does not regain its shape due to this imbalance of pressure.
What is the difference between p-n junction diode and extrinsic semiconductor?
Answer:
The difference between P-N junction diode and extrinsic semiconductor is the allowable direction of flow of current
The extrinsic semiconductor can allow current to flow in both directions while the P-N junction diode permits only a unidirectional flow of current
Explanation:
A semiconductor is a substance that has an intermediate conductivity between that of conductors and non conductors
Examples of semiconductors include germanium and cadmium selenide
A semiconductor to which impurities has been added (an activity known as doping) is an extrinsic semiconductor
Based on the functioning of a semiconductor, doping result in the formation of one of two types of semiconductors including;
1) N-type semiconductor that has an extra electron and the charge carriers are electrons
2) P-type semiconductor that has one less (-e⁻) electron and holes are the charge carriers
An extrinsic semiconductor can conduct allow the flow of electricity in both ways
A P-N junction diode consists of both the P and N-type extrinsic semiconductors arranged such that current can flow in only one direction.
Therefore, the difference is that the extrinsic semiconductor can allow current flow in both directions while the P-N junction diode permits only a unidirectional flow of current.
Concrete and steel expand to almost the same amount when they are heated. Explain why you think this is lucky?
Answer:
While making a bridge or a building, the first thing that comes to our mind is that these are always made by the combination of concrete and steel. Concrete is cheap, but it has the property of breaking when it is twisted or under tension. Steel is expensive, If we made the whole thing with it, it will cost a lot. To provide strength under a reasonable cost, we use the combination of concrete and steel. Another postive point which they have together is that they both expand equally under heat, because they have the same coefficient of thermal expansion. It proves really useful, because if they had different coefficients of thermal expansions, one would expand more than the other, which will create tensions in the mixture and would break it easily. In the case, many cracks would start to appear in the bridge or buildings, which will eventually break them.
If the world was not tilted, what would happen to the people living on Earth
Answer:
Image result for If the world was not tilted, what would happen to the people living on Earth
If the Earth weren't tilted on its axis, there would be no seasons. And humanity would suffer. When a Mars-size object collided with Earth 4.5 billion years ago, it knocked off a chunk that would become the moon. It also tilted Earth sideways a bit, so that our planet now orbits the sun on a slant
Explanation: i looked up the answer
Answer:
we would all maybe fall are sink in to the ground.
Explanation:
18. Which does not affect the strength of an electromagnet?
A the current in the solenoid
B the temperature of the coil
OC the number of loops in the coil
D the type of ferromagnetic core
Answer:
The temperature does not affect the strength of a magnetExplanation:
An electromagnet is obtained by winding an insulated wire round a soft iron rod with the wire ends connected to a DC source. such magnets have temporary magnetic properties which disappears with time as the current supply is cut off.
Furthermore the strength off an electromagnet
increases as current increasesincreases as the number of turns increasesthe type of magnetic core is highly essential as an iron core will do batter than a silver core
A wave is sent down a thick rope that is attached to a thinner rope. What happens when the wave reaches the junction? Explain in words, or draw a diagram.
Answer:
A fraction of the wave will be reflected at the junction and the remainder will be transmitted through the junction into the thin rope
Explanation:
When the junction of the thin and the thick rope is reached by the wave, the wave behaves in the following two ways;
1) A fraction of the incident wave from the thick rope to the junction/boundary of the thin rope will be reflected back to in the direction of the thick rope with a lower amplitude and upright
2) A fraction of the incident wave from the thick rope to the junction/boundary of the thin rope will be transmitted through the thin rope such that the transmitted pulse on the thin rope will have an higher amplitude than that of the thick rope due to the available energy in the wave pulse and the lesser weight of the thin rope.
why the shape of the earth is spherical
Answer:
The Earth is massive enough that the pull of gravity maintains its roughly spherical shape. Most of its deviation from spherical stems from the centrifugal force caused by rotation around its north-south axis. This force deforms the sphere into an oblate ellipsoid.
100 joule of heat produced each 1 secomd on 4ohm find the potential difference
Answer:
20 V
Explanation:
Power is 100 J/s or 100 W.
We know that P = IV = [tex]\frac{V^{2} }{R}[/tex] .
Isolate the potential difference. V = [tex]\sqrt{RP}[/tex] = [tex]\sqrt{100 * 4}[/tex] = 20 V
how many chromosomes will an elephant's sperm have ?
Write down any four points that should be considered during household wiring
Answer:
USE RUBBER CLOVES
USE A PLIER
USE CONDUCTIVE WIRES
SWITHC OFF THE MAIN SWITCH WHILE WIRRING
Explanation:
What is the name of the change in state by which some more energetic molecules in a liquid leave the surface, leaving the rest of the liquid slightly cooler.
Answer:
evaporation
Explanation:
vapor is having higher temperature (also energy) that the liquid it left behind.
that's why the water vapor leave the surface of water which can only have a maximum temperature as 100°C
A sound wave in air has a frequency of 354 Hz and travels with a speed of 343 m/s. How far apart are the wave crests in meters.
Given :
The frequency of travelling sound = f = 282 Hz
The speed of travelling sound = c = 343 m/s
To Find :
The distance of waves crests
Solution :
∵ wavelength of sound wave =
i.e =
Or, =
∴ = 1.12 m
So, The wavelength of sound wave = = 1.21 m
Thus , The distance of waves crests =wavelength of sound wave = 1.21 m
Hence, The distance of waves crests is 1.21 meters Answer
Standing on top of a building, Bob tosses a baseball straight up with an initial speed of 15 m/s. It takes 4.0 s for the ball to hit the ground. What is the vertical distance of the building? (g = -9.8 m/s²)
Answer:
48.26 m
Explanation:
time to goes up (till stop for a while in the air - maximum height)
vt = vo + a t
0 = 15 + g . t
0 = 15 + (-9.8) . t
9.8t = 15
t = 1.531 s
so the time left to goes down is
4.0 - 1.531 = 2.469 s
height from the top of building can find it by using
vo =√(2gh)
15 = √(2)(9.8).h
15² = 19.6h
h = 225/19.6 = 11.48 m
so the distance of maximum height to the ground is
t = √(2H/g)
2.469 = √(2H/9.8)
2.469² = 2H/9.8
6.096 = 2H/9.8
2H = 6.096 x 9.8 = 59.74 m
so the vertical distance of the building (or the building height's is)
H - h = 59.74 - 11.48 = 48.26 m
Identical point charges (+50 x 10 power -6C) are placed at the corners of a square with sides of 2.0-m length. How much external energy is required to bring a fifth identical charge from infinity to the geometric center of the square?
Answer:
636.4 J
Explanation:
The potential energy between one of the charges at the corner of the square and the fifth identical charge is U = kq²/r where q = charge = +50 × 10⁻⁶ C and r = distance from center of square. = √2 m (since the midpoint of the sides = 1 m, so the distance from the charge at the corner to the center is thus √(1² + 1²) = √2)
Since we have four charges, the additional potential energy to move the charge to the centre of the square is U' = 4U = 4kq²/r
U' = 4kq²/r
= 4 × 9 × 10⁹ Nm²/C² (+50 × 10⁻⁶ C)²/√2 m
= 900 Nm²/√2 m
= 636.4 J
The total external energy required is 636.4 J.
Electric potential energy:
According to the question, a square of side a = 2m has 4 identical charges on the corners with charge Q = 50×10⁻⁶C.
A fifth identical charge is brought at the geometric center of the square. The geometric center is at the center of the diagonal:
[tex]r=\frac{a}{\sqrt{2} }=\sqrt{2}\;m[/tex]
The potential energy is a state function which means that it depends on the initial and final position.
Now the energy required is equal to the change in potential energy
[tex]\Delta U=\frac{1}{4\pi\epsilon_o}\frac{4Q^2}{r}\\\\\Delta U=\frac{4\times9\times10^9\times(50\times10^{-6})^2}{\sqrt{2} } \\\\\Delta U=636.4\;J[/tex]
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A train is moving west with an initial velocity of 20m/s accelerates at 4m/s for 10 seconds during this time the train moves a distance
Answer:
400m
Explanation:
From Newton's law of motion;
S = ut + 1/2 at2
Where U is initial velocity
a is acceleration
t is velocity hence;
S is distance covered
S = 20×10 + 1/2 × 4×(10)^2
= 200 + 200 = 400m
A force of 12N acts to the left on a body and a force of 16 N acts to the right . The size and direction of resultant force is
1)4N
2)28N to the right
3) 4 N to the right
Answer:
4 N to the rightExplanation:
The force acting to the right of the body is acting in the positive x direction while the force acting to the left of the body is acting in the negative x direction.
If a force of 12N acts to the left on a body and a force of 16 N acts to the right, force acting to the left will be -12N while that acting to the right will be +16N.
The resultant force acting on the bod will be the sum of the two forces.
Resultant = -12N+16N
Resultant = 4N
The direction of the resultant force will be towards the right since the resultant is a positive value.
Describe how a change in resistance would affect the current in a circuit.
Explanation:
The relation between potential difference, current and resistance flowing in a circuit is given by using Ohm's law. It can be given by :
V = IR
[tex]I=\dfrac{V}{R}[/tex]
Resistance opposes the flow of electric current in the circuit. It means that, if resistance is more, less current will flow through the circuit.
Which of the following does NOT use a turbine?
A. Windmills
B. Nuclear power plants
C. Solar panels
D. Geothermal generation station
Answer:
laa a
Explanation:poque usairea ye aire tienfe luza preopia mkr
Answer:
Solar Panels
Explanation:
A metal rod has a moves with a constant velocity of 40 cm/s along two parallel metal rails through a magnetic field of 0.575 T. If the rails are separated by 20 cm, what is the power generated by the rod? O 341 x 1ow O 6.98 x 103 w O 9.00x 10sw O 8.10 x 105w
Answer:
2.12/R mW
Explanation:
The electrical power, P generated by the rod is
P = B²L²v²/R where B = magnetic field = 0.575 T, L = length of metal rod = separation of metal rails = 20 cm = 0.2 m, v = velocity of metal rod = 40 cm/s = 0.4 m/s and R = resistance of rod = ?
So, the induced emf on the conductor is
E = BLv
= 0.575 T × 0.2 m × 0.4 m/s
= 0.046 V
= 46 mV
The electrical power, P generated by the rod is
P = B²L²v²/R
= B²L²v²/R
So, P = (0.575 T)² × (0.2 m)² × (0.4 m/s)²
= 0.002116/R W
= 2.12/R mW
write the different between the fall of a parachute on earth and its fall on the moon?on what condition does a body have free fall?
Answer:
Shown from explanation
Explanation:
You have heard that expression what ever goes up must come down that's usually used to mean when you throw an object up, it comes down on its accord. This is due to a force on the earth that occurs in nature known as gravity.
So when an object falls under this influence it's said to fall freely.
Note not all heavenly bodies have gravitational pull, from experience by scientists who went to the moon they found out whatever goes up keeps flying endlessly so in that case an external force is needed to keep objects in the moon on ground level.
Hence the parachute falls on earth freely without an external force but on the moon it must fall with an external force inputed on the parachute system.
This means in the earth we have free fall but in the moon no such thing exist. So a body falls freely when there is gravity.
A student with a mass of 66.0 kg climbs a staircase in 44.0 s. If the distance between the base and the top of the staircase is 14.0 m, how much power will the student deliver by climbing the stairs
[tex]power = 205.8 \: watt \\ solution \\ mass = 66 \: kg \\ time = 44 \: sec \\ distance = 14 \\ now \\ power = \frac{w}{t} \\ \: \: \: \: \: \: \: \: = \frac{f \times d}{t} \\ \: \: \: \: \: = \frac{m \times g \times d}{t} \\ \: \: \: \: \: \: = \frac{66 \times 9.8 \times 14}{44} \\ \: \: \: \: = \frac{9055.2}{44} \\ \: \: \: \: \: = 205.8 \: watt \\ hope \: it \: helps[/tex]
Is there a link between number of bulbs and current drawn from the power pack?
Answer:
Yes, there a link between number of bulbs and current drawn from the power pack.
Explanation:
In an Electrical circuit, we have resistors present in that circuit. These resistors can be connected in two ways.
a) Series connection
b) Parallel connection
There is a link or a relationship between number of bulbs and the current drawn from the power pack. This is because the number of bulbs is equivalent to or equal to the number of resistors.
Hence,
a) In a series connection, the link or relationship between the number of bulbs(resistors) is as the number of light bulbs increases, the current in the power pack (circuit) decreases.
b) In a parallel connection, the link or relationship between the number of bulbs(resistors) is as the number of light bulbs increases, the current in the power pack (circuit) increases.
Which thermodynamic process takes place at a constant temperature so that the internal energy of a system remains unchanged?
A.
the isovolumetric process
B.
the isobaric process
C.
the adiabatic process
D.
the isothermal process
Answer:
D
Explanation:
Isothermal process is one that occurs on constant temperature example the vaporisation of water on boiling in an enclosed space .
At this time the temperature of the system remains constant .
Answer:
D. the isothermal process
Explanation:
Las ruedas de una locomotora de 500 toneladas tiene un coeficiente de friccion estatico con las vias de 0.15 ¿Cual es la fuerza de traccion tangencial maxima ejercida entre las vias y las ruedas?
Answer:
Ff = 7.35*10^5 N
Explanation:
To find the maximum transverse pulling force you use the following formula, for the friction force:
[tex]F_f=\mu N=\mu Mg[/tex] (1)
μ: friction coefficient = 0.15
N: normal force, which is equal to the weight over the wheel
M: mass of th train = 500 ton = 500 000 kg
g: gravitational acceleration = 9.8 m/s^2
You replace the values of the variables in the equation (1):
[tex]F_f=(0.15)(500000kg)(9.8m/s^2)=735000 N=7.35*10^5N[/tex]
hence, the maximum transverse pulling force is 7.35*10^5 N
Who is prime minister of india
His name is
Narendra Modi
Answer:
Hey!
*its kinda the wrong topic but ill answer anyway!!!*
The Prime Minister of India is...
Narendra ModiExplanation:
HOPE THIS HELPS!!
A motorbike and its rider have a mass of 275 kg. If they experience an acceleration of 4.50 m/s?,
what force was exerted on them?
Answer:
1237.5N
Explanation:
Recall that F = ma ........1
Where F is the applied force in Newton
M is the mass in kg
And a is the acceleration in meter per seconds.
F = ?
Mass = 275kg
a = 4.50 m/s^2
Substituting the values into equation 1
F = 275kg × 4.50 m/s^2
F = 1237.5N
The force exerted on them will be 1237.5N
find the period of a simple pendulum of 1m length placed on earth and on moon g on moon =1.67m/s² g on earth=10m/s²
Answer:
[tex]T_{m }[/tex] = 4.86 s
[tex]T_{e}[/tex] = 1.98 s
Explanation:
Given:
Length = l = 1 m
Acceleration due to gravity of moon = [tex]g_{m}[/tex] = 1.67 m/s²
Acceleration due to gravity of Earth = [tex]g_{e}[/tex] = 10 m/s²
Required:
Time period = T = ?
Formula:
T = 2π [tex]\sqrt{\frac{l}{g} }[/tex]
Solution:
For moon
Putting the givens,
T = 2(3.14) [tex]\sqrt{\frac{1}{1.67} }[/tex]
T = 6.3 [tex]\sqrt{0.6}[/tex]
T = 6.3 × 0.77
T = 4.86 sec
For Earth,
Putting the givens
T = 2π [tex]\sqrt{\frac{1}{10} }[/tex]
T = 2(3.14) [tex]\sqrt{0.1}[/tex]
T = 6.3 × 0.32
T = 1.98 sec
How does charging by conduction work?
Answer:
During charging by conduction, both objects acquire the same type of charge. If a negative object is used to charge a neutral object, then both objects become charged negatively. ... In this case, electrons are transferred from the neutral object to the positively charged rod and the sphere becomes charged positively.
can someone put these in the right order please