Answer:
15%
Explanation:
Step one:
Given data
Energy source= 300J
Useful energy = 45J
Waste energy = 255J
Required
The efficiency of the solar system
Step two:
The efficiency is computed by factoring only the useful work and the energy source
Efficiency= 45/300*100
Efficiency= 0.15*100
Efficiency= 15%
Which of the following statements about infrared telescopes is NOT true?
a. They are typically operated at lower temperatures.
b. They are especially helpful for viewing cool or obscured astronomical objects.
c. They were first built in the 1960s.
d. They are often placed on mountaintops.
e. They do not work well at high altitudes.
Answer:
a. They are typically operated at lower temperatures.
a. They are typically operated at lower temperatures.b. They are especially helpful for viewing cool or obscured astronomical objects.
What happens when two sound waves meet in destructive interference?
sorry i did not mean to answer
A horizontal net force is exerted on a 2.0 kg object at rest. The object starts at x=0 m and travels 8.0 m along a horizontal frictionless surface.
What is the velocity of the object
Round answer to 2 significant digits
____ m/s
There's a constant force of 35 N exerted on the object of mass 2.0 kg, so it undergoes an acceleration a of
35 N = (2.0 kg) a → a = 17.5 m/s²
The object travels 8.0 m, so that it attains a velocity v of
v ² = 2 (17.5 m/s²) (8.0 m) → v ≈ 16.73 m/s ≈ 17 m/s
The velocity of the 2 Kg object which travels 8 m along the horizontal frictionless surface is 17 m/s
How to determine the acceleration Force (F) = 35 NMass (m) = 2 KgAcceleration (a) =?a = F / m
a = 35 / 2
a = 17.5 m/s²
How to determine the velocity Initial velocity (u) = 0 m/sDistance (s) = 8 mAcceleration (a) = 17.5 m/s²Final velocity (v) =?v² = u² + 2as
v² = 0² + (2 × 17.5 × 8)
v² = 280
Take the square root of both side
v = √280
v = 17 m/s
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Write a story that includes (in order) the 7 waves of the electromagnetic spectrum. Try incorporating a characteristic about each type of wave. Bold or highlight them.
Answer:
sorry im doing a challenge but i will have someone answer it
Explanation:
A 0.5 kg football is thrown so that it has a momentum of 16 kg*m/s. What is its speed?
Explain how the law of conservation of energy applied to the energy transformations that occur from the outlet charger to the ringing phone
Answer: ELECTRICAL ENERGY to CHEMICAL ENERGY to SOUND ENERGY.
Explanation:
There are laws governing the conservation of energy in physics. The first law of thermodynamics states that in a closed system, energy can neither be created nor destroyed during transformation. With this, the total energy of a given system always remains constant.
This first law of thermodynamics which arouse from special relativity, says that changes in the energy of systems will also coincide with changes in a measure of its energy content.
The ELECTRICAL energy from the outlet charger is transformed and stored as CHEMICAL energy in the battery of the phone. This in turn is converted to SOUND energy when the phone rings.
what do you understand by the term current state and define its SI unit.........
Answer:
Explanation:
Current refer to the rate at which electric charge flow or run or move in an electric circuit . It is measured in Ampere or coulumb per second.
The SI unit is Ampere and it is represented by A. It is a scalar quantity.
1 Ampere is the current that will produce an attractive force of 2 × 10^-7 Newton per meter of length between two parallel conductors.
please help me answer these
The energy of a given wave in the electromagnetic spectrum is 2.64 × 10-21 joules, and the value of Planck’s constant is 6.6 × 10-34 joule·seconds. What is the value of the frequency of the wave?
Answer:
4.00 × 1012 hertz
Explanation:
An object is spun around in circular motion such that its frequency is 12 Hz.
a. What is the period of its rotation?
b. How much time will be required to complete 86 rotations?
Explanation:
Given parameters:
Frequency = 12Hz
Unknown:
a. Period of its rotation
b. Time required to complete 86 rotations
Solution:
Frequency is the number of times of rotation per unit of time.
Frequency = [tex]\frac{n}{t}[/tex]
Period is the opposite of frequency;
Period = [tex]\frac{1}{12}[/tex] = 0.083s
b. Time for 86 rotations;
Since frequency = [tex]\frac{n}{t}[/tex]
n is the number of rotation
t is the time
t = [tex]\frac{n}{Frequency}[/tex] = [tex]\frac{86}{12}[/tex] = 7.2s
The period of rotation is 1/12 seconds and it takes 7.17 seconds to complete 86 rotations.
Time period (T) in a rotational or periodic motion is defined as the time taken to complete one rotation and frequency (f) is the reciprocal of time period.
f = 1/T ⇒ T = 1/f , given that f = 12 Hz
T = 1/12 s is the time period of ne rotation
Now if time takes to complete one rotation is 1/12s , then to complete 86 rotation, the time required is
t = 86×(1/12) = 7.17 seconds is taken to complete 86 rotations.
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Most metals have...
a. Atoms that are spread out, and low specific heats
b. Atoms that are close, and low specific heats
c. Atoms that are spread out, and high specific heats
d. Atoms that are close, and high specific heats
What does it mean that photographs are two-dimensional?
If the sun were to collapse into a black hole, what would the radius be?
Answer:
If the Sun, with its mass of 1 MSun, were to become a black hole the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass
Answer:
It would be 1/3rd size of a neutron star
Explanation:
the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass.
In an open circuit ____________.
Question 34 options:
a light bulb would produce light
current will flow
current will not flow
more than one resistor is in the circuit
a resistor controls the flow of current
Answer:
The current will not flow
Explanation:
An open circuit is a circuit that is not complete it has an opening Therfor the current can not flow.
define time in short answer
Answer:
measurable period during which an action, process, or condition exists or continues
Explanation:
Answer:
Time is the indefinite continued progress of existence and events that occur in an apparently irreversible succession from the past, through the present, into the future.
Explanation:
hope it helps...
How will recreation be affected by sea level rise?
Answer:
Scientists predict that sea levels could rise up to six-feet by 2100. An increase this large will swallow beaches—impacting public access, beach recreation, and healthy ecosystems. ... With less sand beach-goers will have a completely different recreational experience in the future.
Explanation:
What is the explanation for the fact that the desert sand is very hot in the day and very cool at night? 1. Sand reflects light very well.
2. Sand is a bad heat conductor.
3. Sand has a low specific heat compared to air
why is g called the universal gravitational constant
Explanation:
Hey there!
Universal gravitation constant (g) is the force of gravitation produced between two bodies of unit mass each separated by unit distance between their centers. The value of universal gravitation constant (g) is 6.67 Nm²/kg², which is constant all over the world. So, that's why it is called universal gravitation constant.
Hope it helps....
I need help please
What % of offspring will be green?
Answer:
50%
Explanation:
Gg = 50%
gg = 50%
are these punnet squares?
Which of these is used to find the estimated age range of a fossil? Group of answer choices Absolute dating Half-life Index fossils Radioactive dating
Answer:
Radioactive Dating
Explanation:
To get the age range of rocks or fossils, researchers usually make use of radiometric dating technique which is also called radioactive dating. Now, this radioactive dating is based on the principle of comparison between the abundance that's observed from a naturally occurring radioactive isotope including its decay products, with the use of known decay rates.
Why is a protective apron or lab coat important to use when working with acids?
Acids conduct electricity and contact could cause a shock.
Acids react with lipids and can cause damage to skin tissue.
Acids break down fabrics and can cause burns if the acids are strong.
Acids have a slippery feel and could result in a fall.
Answer:
Acids break down fabrics and can cause burns if the acids are strong.
Explanation:
A protective apron or lab coat is important when working with acids because acids break down fabrics and can cause burns if the acids are strong.
An acid is a substance that interacts with water to produce excess hydroxonium ions in an aqueous solution. A strong acid ionizes completely in solution. When they come in contact with a fabric, they break them down violently. So, if they come in contact with the skin, it causes a violent break down of body tissues. The apron acts a protective layer.Answer:
C
Explanation:
I got it right
A ‘thermal tap’ used in a certain apparatus consists of a silica rod which
fits tightly inside an aluminium tube whose internal diameter is 8mm at
0
0C. When the temperature is raised, the fit is no longer exact. Calculate
what change in temperature is necessary to produce a channel whose
cross-section is equal to that of a tube of 1mm internal diameter. (linear
expansivity of silica = 8X10-6
/K and linear expansivity of aluminium =
26X10-6
/K )
Correct question is;
A thermal tap used in a certain apparatus consists of a silica rod which fits tightly inside an aluminium tube whose internal diameter is 8mm at 0°C.When the temperature is raised ,the fits is no longer exact. Calculate what change in temperature is necessary to produce a channel whose cross-sectional is equal to that of the tube of 1mm. (linear expansivity of silica = 8 × 10^(-6) /K and linear expansivity of aluminium = 26 × 10^(-6) /K).
Answer:
ΔT = 268.67K
Explanation:
We are given;
d1 = 8mm
d2 = 1mm
At standard temperature and pressure conditions, the temperature is 273K.
Thus; Initial temperature; T1 = 273K,
Using the combined gas law, we have;
P1×V1/T1 = P2×V2/T2
The pressure is constant and so P1 = P2. They will cancel out in the combined gas law to give:
V1/T1 = V2/T2
Now, volume of the tube is given by the formula;V = Area × height = Ah
Thus;
V1 = (πd1²/4)h
V2 = (π(d2)²/4)h
Thus;
(πd1²/4)h/T1 = (π(d2)²/4)h/T2
π, h and 4 will cancel out to give;
d1²/T1 = (d2)²/T2
T2 = ((d2)² × T1)/d1²
T2 = (1² × T1)/8²
T2 = 273/64
T2 = 4.23K
Therefore, Change in temperature is; ΔT = T2 - T1
ΔT = 273 - 4.23
ΔT = 268.67K
Thus, the temperature decreased to 268.67K
A funnel shaped low pressure system that is typically associated with strong thunderstorms is a(n)_______. *
Answer:
Tornadoes
A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloudExplanation:
Calculate the Net force from the above Freebody diagram and data table.
answer 4
Explanation:
Tyler and his family drove from Atlanta to Baltimore. They traveled a total of 678 miles over 2 days.
What is the reference point in this scenario?
Atlanta
Baltimore
678 miles
2 days
Answer:
atlanta
Explanation:
just took the test
The reference point in this scenario is Atlanta.
What is reference point of the journey?The can be described as the starting point of the entire journey.
From the given statements the family started the journey from Atlanta and then traveled to Baltimore.
Atlanta is the start point (reference point) while Baltimore is the destination (finishing point).
Thus, the reference point in this scenario is Atlanta.
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DUE RIGHT NOW
IT WOULD BE NICE IF YOU EXPLAIN TO
Answer: 0-3 minutes
Explanation:
On the side of the graph, it shows you the distance the car was moving. As you know, MPH (miles per hour) shows how fast an object is moving, meaning that the car was going around 0-1 mph around minutes 0-3. Just make sure you know how to read a graph and this will become an easy question for you :)
Answer:
5-8 minutes the car isn't traveling. The g above is wrong
Explanation:
What is the speed of a wave that has a frequency of 220 Hz and a wavelength of 0.39 m
Answer:
85.8 m/s
Explanation:
speed=wavelength multiply by frequency
[tex]0.39 \times 220 [/tex]
[tex]85.8[/tex]
What percent of offspring will be brown eyed?
25%
50%
75%
100%
Please I need help
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Explanation:
Uppercase B is the brown eyed gene. It's dominant over the recessive gene lowercase b, which is for blue eyes. Convention has the uppercase letter always dominate over the lowercase recessive gene.
Note the genotypes of the offspring are all Bb. This tells us we have nothing but brown eye offspring. The visual indicator also shows four brown eyes, which backs up each Bb genotype. The phenotype is the observed brown eyes that others can see, while the genotype deals with the gene pairings.
Since four offspring out of four total have brown eyes, this means the percent of brown-eyed offspring is 4/4 = 1.00 = 100%
Work done by friction?
increases kinetic energy of body
decreases kinetic energy of body
increases potential energy of body
decreases potential energy of body
increase kinetic energy of body
Answer:
yes it increases kinetic energy of body on which it is applying it also cause heat loss
Who invented scuba?
1. Benjamin Franklin
2. Mathew Maury
3. Robert Falcon Scot
4. Cousteau and Gagnon
Answer:
2. Mathew Maury
Explanation:
2. Mathew Maury
4. Cousteau and Gagnon
Explanation:
they made the first successful scuba in 1942