Carbon-Based Fuels Dominate Global Energy Use
Crude oil, coal, and natural gas supply about 85% of the energy used in the world. Fossil fuels are valuable as sources of energy because they contain hydrocarbons and other carbon-based materials.
On clear day, sunlight delivers approximately 1000 J each second to a 1 m2 surface; smaller areas receive proportionally less--half the area receives half the energy. A 12% efficient solar cell, a square 12 cm on a side, is in bright sunlight.
How much electric power does it produce?
The direct proportions rule allows to find the result for the energy produced by a solar cell is:
E = 1,728 J
The efficiency of a solar cell is the percentage of incident energy that transforms into electricity.
The direct proportions rule or three rule stable that if two quantities are proportional the product remains constant.
They indicate that the length of the solar cell is l = 12 cm = 0.12m. Let's find the area of the solar cell.
A = l²
A = 0.12²
A = 1.44 10⁻² m²
Let's use a direct proportion rule. If 1 m² receives 1000J of energy, how much does an area of 1.44 10⁻² m² receive?
Energy_cell = 1000 J ( [tex]\frac{1.44 \ 10^{-2}}{1}[/tex] )
Energy_ cell = 14.4 J
Let's use another direct ratio rule for efficiency.
[tex]Energy_{produced} = Energy_{cell} \frac{12}{100} \\Energy_{produced} = 14.4 0.12 \\Energy_{produced} = 1.728 J[/tex]
In conclusion using the direct proportions rule we can find the result for the energy produced by a solar cell is:
E = 1,728 J
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7. A 1.0 kg metal head of a geology hammer strikes a solid rock with a velocity of 5.0 m/s. Assuming all the energy is retained by the hammer head, how much will its temperature increase
The increase in temperature of the metal hammer is 0.028 ⁰C.
The given parameters:
mass of the metal hammer, m = 1.0 kgspeed of the hammer, v = 5.0 m/sspecific heat capacity of iron, 450 J/kg⁰CThe increase in temperature of the metal hammer is calculated as follows;
[tex]Q = K.E\\\\mc \Delta T = \frac{1}{2} mv^2\\\\\Delta T = \frac{v^2}{2 c}[/tex]
where;
c is the specific heat capacity of the metal hammer
Assuming the metal hammer is iron, c = 450 J/kg⁰C
[tex]\Delta T = \frac{5^2}{2 \times 450} \\\\\Delta T = 0.028 \ ^0C[/tex]
Thus, the increase in temperature of the metal hammer is 0.028 ⁰C.
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Two point particles, with masses m and 2 m, are separated by some distance Lin an uniform gravitational field. The center of gravity of this two particle system is:________
А. located L/2 distance away from either mass and on the line joining the two particles.
B. located 1/3 distance away from 2 m and on the line joining the two particles.
C. located L/4 distance away from 2 m and on the line joining the two particles.
D. located L/3 distance away from mand on the line joining the two particles.
E. located L/4 distance away from m and on the line joining the two particles.
F. located where the mass 2 m is located.
The center of gravity of this two particle system is located 1/3 distance away from 2 m and on the line joining the two particles.
The given parameters:
Mass of the first particle, = mMass of the second particle, = 2mDistance between the two particles, = LThe center of gravity of the two particles when first particle is fixed is calculated as;
[tex]C_G = \frac{m(0 ) \ +2m(L) }{m+ 2m} \\\\C_G = \frac{2mL}{3m} \\\\C_G = \frac{2L}{3}[/tex]
The center of gravity of the two particles when second particle is fixed is calculated as;
[tex]C_G = \frac{m(L) \ + \ 2m(0)}{m + 2m} \\\\C_G = \frac{mL}{3m} \\\\C_G = \frac{L}{3}[/tex]
Thus, the center of gravity of this two particle system is located 1/3 distance away from 2 m and on the line joining the two particles.
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2. Match the term to the definition
1. Reversibility
a. A break between activities during a workout.
2. Overload
3. Progression
4 Duration
5. Rest
b. Length of an individual workout.
c. The Improvement seen when you are training will be lost if you stop
training.
d. Moving forward through a sequence to gradually build up the body.
e Number of training sessions per week.
f. Level of difficulty of your workout.
9. Improvements will only be seen in the areas that you work on.
h The time between workouts that allows your body to heal and adapt to
the stress from your workout.
6. Recovery
7. Frequency
8. Specificity
1. Increase the amount of stress you put on your body.
9. Intensity
what is translator disadvantage?
Machine translators:
Level of accuracy can be very low.
Accuracy is also very inconsistent across different languages.
Machines can't translate context.
Mistakes are sometimes costly.
Sometimes translation simply doesn't work.
Human translators:
Turnaround time is longer.
Translators rarely work for free.
Unless you use a translation agency, with access to thousands of translators, you're limited to the languages any one translator can work with.
Calculate the amount of work done (in joules) to raise the 0.2kg mass 0.5 m
Answer:
1
Explanation:
A=mgh=0.2*10*0.5=1 J
Which of the following best describes an achievement test that is given at the end of a learning segment to evaluate mastery of objectives?
Answer
An Achievement test is an assessment of developed knowledge or skill. ... Achievement tests are developed to measure skills and knowledge learned in a given grade level, usually through planned instruction, such as training or classroom instruction. Achievement tests are often contrasted with aptitude tests.
Explanation:
What are the two factors that affect the frictional force between objects
A 30.0-g object moving to the right at 20.5 cm/s overtakes and collides elastically with a 13.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. (Take the positive direction to be to the right. Indicate the direction with the sign of your answer.)
Let m₁ and m₂ be the masses of the two objects, and v₁ and v₂ their initial velocities. So
m₁ = 30.0 g = 0.0300 kg
m₂ = 13.0 g = 0.0130 kg
v₁ = + 20.5 cm/s = 0.205 m/s
v₂ = + 15.0 cm/s = 0.150 m/s
and we want to find v₁' and v₂', the final velocities of either object after their collision.
Momentum is conserved throughout the objects' collision, so that
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
where v₁' and v₂' are the first and second object's velocities after the collision.
Kinetic energy is also conserved, so that
1/2 m₁v₁² + 1/2 m₂v₂² = 1/2 m₁(v₁')² + 1/2 m₂(v₂')²
or
m₁v₁² + m₂v₂² = m₁(v₁')² + m₂(v₂')²
From the first equation (omitting units), we have
0.0300 • 0.205 + 0.0130 • 0.150 = 0.0300 v₁' + 0.0130 v₂'
0.0810 = 0.0300 v₁' + 0.0130 v₂'
81 = 30 v₁' + 13 v₂'
From the second equation,
0.0300 • 0.205² + 0.0130 • 0.150² = 0.0300 (v₁')² + 0.0130 (v₂')²
0.00155 ≈ 0.0300 (v₁')² + 0.0130 (v₂')²
1.55 ≈ 30 (v₁')² + 13 (v₂')²
Solving both equations simultaneously gives two solutions, one of which corresponds to the initial conditions. The other yields
v₁' ≈ + 0.172 m/s
and
v₂' ≈ + 0.227 m/s
A car is traveling at 8 m/s accelerates at 3.1 m/s^2 to reach a final top speed of 56 m/s. How much time will pass before the car reaches its top speed
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
WILL MARK BRAINLIEST
1. What is the difference between distance and displacement?
A. Distance is measured in feet. Displacement is measured in meters
B. Distance is the difference between how quickly you move between two points. Displacement is the average of that motion
C. Distance is a measure of length of travel. Displacement is the measure of the time it takes to move that length
D. Distance is the length of travel. Displacement is the straight line distance between the starting point and the ending point
2. When forces are in opposite directions, they subtract from one another
A. True
B. False
3. When two forces are in opposite directions, and they are the exact same magnitude, the forces will
A. Subtract from each other
B. Cancel Out
C. Go on Infinitely
D. eventually reach equilibrium
4. Acceleration is a change in motion over time
True or False
Answer:
1. C
2. True
3. D
4. True
Explanation:
While distance refers to “how much land an object has traversed throughout its journey,” displacement measures “how far an object is out of place.” In this post, let's look at the difference between distance and displacement. Thus, option C is correct.
What are the distance and displacement?Displacement and distance are two distinct ideas. The total distance travelled is larger than the displacement between those two points if an object changes direction while travelling.
Distance is the length of any path connecting any two places. Displacement is the straight-line distance between any two points when calculated along the shortest route.
Therefore, The direction is ignored when calculating distance. The direction is accounted for in the displacement calculation.
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Name two environmental factors, one natural and one human-made, that could account for the trend or pattern in bird (quail, wren) and rodent (mice, rabbits) populations before 1997. Help!
Factors such as more crops, fewer predators, invasive species, and changes in the environment explain a decrease or increase in the birds and rodent populations.
Before 1997, both rodents and birds populations increased due to different factors. Moreover, these factors can be classified as natural or human-made factors. Here are the factors that mainly affected these animals:
Bird population:
Increase:
Decrease in predators that increase birds chances to survive (natural factor)
Increase in crops that improve food access for birds (human factor)
Decrease:
Invasive species or increase of predators (natural factor)
Destruction of natural habitats due to an increase in industry and extraction (human factor)
Rodent population:
Increase:
More adaptability that increased rodents chances to survive (natural factor)Increase in crops that improve food access for rodents (human factor)Decrease:
Invasive species or increase of predators (natural factor)Increase in rabbit consumption and use of rodent control products (human factor)Learn more in: https://brainly.com/question/18123593
URGENTLY NEED HELP!!!!!!
the stretch of a spring and the force it exerts are inversely proportional.
Select one:
O True
O False
Answer:
False.
Explanation:
HIHIHHHHHHHHIHIHIIHIHHHHIHIHIHIHIHIHIHIHIHIHIHIHIHIIH
Answer:
Ok thanks for the points though
Explanation:
If you represented Earth's history by a line that is 1 m long, how long a segment (in cm) would represent the 400 million years since life moved onto the land
The length of the segment that will represent the 400 million years is 8.8 cm.
The given parameters:
length of age of the Earth = 1 meter longage of the Earth = 4.54 billion yearstime to be represented in the given segment = 400 million yearsThe length of the segment that will represent the 400 million years is calculated as follows;
4.54 billion years ------------- 1 m
400 million years ------------- ?
[tex]\frac{1 \ m}{4.54 \times 10^9 \ years} \times 400 \times 10^6 \ years = 0.088 \ m[/tex]
The length of the segment in centimeters (cm) is calculated as follows;
[tex]= 0.088 \ m \times 100 \ cm\\\\= 8.8 \ cm[/tex]
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which of the following statements describes a perfectly inelastic collision
Answer: An ice hockey player picks up a trophy as he slides past it.
Two pool balls colliding precisely inelastically and rebounding off one another is an example. So, the correct option is A.
What is an Inelastic collision?Inelastic collisions are those in which the total kinetic energy is lower after the impact than it was before. The stick is travelling quickly in the direction of the ball before to the contact. The stick comes to a stop following the accident. It transfers some of its kinetic energy to the cue ball, which rolls forward.
The type of collision mentioned in the given example is known as an inelastic collision is one in which the system's momentum is preserved but its kinetic energy is not. In a ballistic pendulum, an example of an inelastic collision. Dropped ball of clay is another illustration of an inelastic collision.
Thus, the correct option is A.
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Your question is incomplete, most probably the complete question is:
Which of the following statements describes a perfectly inelastic collision?
A. Two billiard balls bounce off of each other,
B. A car crashes into a tree and rebounds in the other direction,
C. A wad of chewing gum is thrown and sticks to a moving truck,
D. Two ice skaters hit each other and fall over in opposite directions,
a wave travels at a constant speed. how does the wavelength change if the frequency is reduced by a factor of 3? assume the speed of the wave remains unchanged.
A. the wavelength decreases by a factor of 3
B. the wavelength does not change
C. the wavelength increases by a factor of 3
D. the wavelength increases by a factor of 9
Answer:
b
Explanation:
when the wavelength increase it doesnt affect the frequency of a wave.
Answer: The wavelength increases by a factor of 3
Explanation:
In which of the following situations is the Doppler Effect absent?
The source and the observer are moving towards each other.
The observer is moving toward the source.
The source is moving away from the observer.
The source and the observer are both moving with the same velocity.
Answer:
Correct option is
C
The listener is moving towards the source of sound
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave (or another periodic event) for an observer moving relative to its source.
So if both listener and source of sound are stationary or are moving with the same velocity that is relative velocity is zero, there won't be any change in frequency.
Thus, in this case, the effect will arise when a listener is moving towards the source of the sound.
A car of mass 5000 kg was initially moving at 100 km/h and stops at a distance of 55 m. Find the
magnitude of the net force (in N) acting to stop the car.
Answer:
|F| = 35 kN
Explanation:
a = F/m
100 km/hr(1000 m/km / 3600 s/hr) = 27.8 m/s
v² = u² + 2as
a = (v² - u²) / 2s
F/m = (v² - u²) / 2s
F = m(v² - u²) / 2s
F = 5000(0² - 27.8²) / 2(55)
F = - 35,072.9517...
Which is the best way to avoid plagiarism? O use more than one source from your research O repeat information from your sources O present a topic in your own words O understand your topic before you begin writing
Answer:
O present a topic in your own words
Explanation:
Plagiarism is using someone else's words or work without giving them proper credit. Presenting a topic in your own words means you are not copying anyone.
Answer:
present a topic in your own words
Explanation:
9. The acceleration (a)-time (t) graph of a particle moving in a straight line is as shown in figure. At time t = 0, the velocity of particle is 10 m/s. What is the velocity at t = 8 s?
(1) 2 m/s
(2) 4 m/s
(3) 10 m/s
(4) 12 m/s
Answer:Acceleration - time graph for a particle moving in a straight line is as shown in figure. Change in velocity of the particle from t = 0 to t = 6s is:-.
1 answer
·
Top answer:
Change in velocity = (sum of area of graph) = ( 12 × 4 × 4 ) + ( 12 × ( + 2) ( - 1) ) - 4 = 8 - 4 = 4 x
Explanation:
Find the work done by the force field F in moving an object from A to B. F(x, y) = 6y3/2i + 9x y j A(1, 1), B(3, 4)
Answer:
138
Explanation:
(since there's a blank next to "9x y j", I'm assuming the y of F(x, y) is 9x[tex]\sqrt{y}[/tex] j)
1) find the partial derivative of each:
[tex](6y^{\frac{3}{2} })i + (9x\sqrt{y} )j[/tex]
[tex]f_{x} =(6y^{\frac{3}{2} })_{x} = \int\limits{6y^{\frac{3}{2} }} \, dx = 6xy^{\frac{3}{2} } +c \\\\f_{y} = (9x\sqrt{y} )_{y} = \int\limits{9xy^{\frac{1}{2} } } \, dy = 9x(\frac{2}{3} )y^{\frac{3}{2} } +c = 6xy^{\frac{3}{2} } +c[/tex]
2) use partial integrals to make gradient of f:
take whatever you got from partial integral and add them together (if they repeat, just use it once)
[tex]F =[/tex] Vf (V = gradient of)
[tex]F(x, y) = 6xy^{\frac{3}{2} }[/tex]
3) Evaluate the integrals with given points:
Integral of F dotted with dr = F(point B) - F(point A) = F(3, 4) - F(1, 1)
[tex]F(point B) = 6(3)(4)^{\frac{3}{2} }\\F(Point A) = 6(1)(1)^{\frac{3}{2}}\\F(point B) - F(pointA) = 6(3)(4)^{\frac{3}{2} }-(6(1)(1)^{\frac{3}{2}})[/tex]
= 144 - 6 = 138 units of work
Work done by the force field F in moving an object from A to B = 138 J
Given data :
Force field F(x,y) = [tex]6y^{\frac{3}{2} }i + (9x\sqrt{y} ) j[/tex]
Step 1 : determine the partial derivatives of the vector quantity
Fx = ∫ [tex]6y^{\frac{3}{2} }i = 6xy^{\frac{3}{2} } + c[/tex]
Fy = ∫ [tex](9x \sqrt{y})_{y} = 9x(\frac{2}{3})y^{\frac{3}{2} } + c[/tex]
Equating the partial derivatives :
[tex]9x(\frac{2}{3})y^{\frac{3}{2} } + c[/tex] = [tex]6xy^{\frac{3}{2} } + c[/tex]
therefore the gradient of F i.e. F = vF = F( x,y ) = [tex]6xy^{\frac{3}{2} }[/tex]
Next step : Determine the work done
Work done ( F.dr ) = [ F(point b ) = F( 3,4 ) ] - [ F(point A) = F( 1,1 ) ]
F(3,4 ) = 6(3)(4)[tex]^{\frac{3}{2} }[/tex] = 144
F( 1,1 ) = 6(1)(1)[tex]^{\frac{3}{2} }[/tex] = 6
Therefore the work done by the force field = 144 - 6 = 138 J
Hence we can conclude that the work done by the force field F is = 138 J
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can you classify matter based on chemical properties
Answer:
Explanation:
Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. A chemical substance is composed of one type of atom or molecule.
What happened when a lobster release a claw? a. The lobster attacks with the claw. b. The lobster let the claw go. C. The lobster bites off the claw. D. The lobster eats with the claw.
Answer:b
Explanation:
Answer:
The lobster let the claw go. so, B.
Explanation:
i hope this helps.
Which of the following methods of pest control used in IPM systems is effective because of the increase in biological diversity it provides? timed crop planting O weed suppression composted soil amendments deep tilling soil
Answer:
Decline in soil health is a serious worldwide problem that decreases complexity and stability of agricultural ecosystems, commonly making them more prone to outbreaks of herbivorous insect pests. Potato (Solanum tuberosum L., Solanaceae) and onion (Allium cepa L., Amaryllidaceae) production is currently characterized by high soil disturbance and heavy reliance on synthetic inputs, including insecticides. Evidence suggests that adopting soil conservation techniques often (but not always) increases mortality and decreases reproductive output for the major insect pests of these important vegetable crops. Known mechanisms responsible for such an effect include increases in density and activity of natural enemy populations, enhanced plant defenses, and modified physical characteristics of respective agricultural habitats. However, most research efforts focused on mulches and organic soil amendments, with additional research needed on elucidating effects and their mechanisms for conservation tillage, cover crops, and arbuscular mycorrhizae.
Introduction
Soil erosion is a serious problem worldwide (Amundson et al., 2015). Although it is often overshadowed in public discourse by other concerns, such as climate change and invasive species, soil deterioration receives considerable attention from the scientific community (Montgomery, 2007; Borrelli et al., 2017; Berhe et al., 2018). In addition to the loss of agricultural productivity, soil erosion has been linked to increased emissions of greenhouse gases and reduced water quality (Amundson et al., 2015; Berhe et al., 2018). Global soil erosion is forecasted to increase in the near future because of cropland expansion, especially in the least economically developed areas (Borrelli et al., 2017).
What is the acceleration of a box weighing 596 N if a force of 777 N is applied to it?
Answer:
[tex]12.79 m/s^2[/tex]
Explanation:
1. Apply Newton's 2nd law:
[tex]F=ma[/tex]
2. Use the definition of weight to find the mass of the box:
[tex]W=mg=m=\frac{W}{g}[/tex]
3. Solve for acceleration in Newton's 2nd law and substitute for mass:
[tex]a=\frac{F}{\frac{W}{g} }[/tex]
4. Plug in the given values from the question and assume [tex]g=9.81m/s^2[/tex]:
[tex]a=\frac{777N}{\frac{596N}{9.81m/s^2} } } =12.79m/s^2[/tex]
PLEASE HELP ME GET THIS RIGHT
Explanation:
I'm not sure, but I would go for the more than A since its orbital speed is at its fastest and the sweep occurs in about the same period of days.
Calculate the torque produced by a 50.0 N perpendicular force at the end of a 0.300 m long wrench.
Answer:
Torque = 50N x 0.3m = 15Nm
Explanation:
Torque = Force x length of lever arm. To obtain the torque simply multiply the two given values.
Croquet ball A moving at 8.3 m/s makes a head on collision with ball B of equal mass and initially at rest. Immediately after the collision ball B moves forward at 6.4 m/s .
What fraction of the initial kinetic energy is lost in the collision?
Answer:
0.25
Explanation:
That is the right answer.
The fraction of the initial kinetic energy is lost in the collision is 35.3%.
The given parameters:
Initial velocity of ball A = 8.3 m/sInitial velocity of ball B = 0Final velocity of ball B = 6.4 m/sThe initial kinetic energy of the system collision is calculated as follows;
[tex]K.E_i = \frac{1}{2} mv_1_i^2 + \frac{1}{2} mv_2_i^2\\\\K.E_i = \frac{1}{2} (m)(8.3)^2 + \frac{1}{2} (m) (0)^2\\\\K.E_i = 34.445 m[/tex]
The final velocity of ball A after collision is calculated as follows;
[tex]u_1 + v_1 = u_2 + v_2\\\\8.3 + v_1 = 0 + 6.4\\\\v_1 = 6.4 - 8.3\\\\v_1 = -1.9 \ m/s[/tex]
The final kinetic energy of the system after collision is calculated as follows;
[tex]K.E_f = \frac{1}{2} m(-1.9)^2 + \frac{1}{2} m(6.4)^2\\\\K.E_f = 22.285 \ m \[/tex]
The fraction of the initial kinetic energy is lost in the collision is calculated as follows;
[tex]= \frac{K_i - K_f}{K_i} \\\\= \frac{34.445 - 22.285}{34.445} \\\\= 0.353\\\\= 35.3\%[/tex]
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The Greek root astro means "stars." Use the context clues to choose the correct definition of the word astronomer. According to the astronomer, the bigger the telescope, the more detail we can see in the images. O A. a person who studies astronauts O B. a person who studies the stars O C. a person who tells the future O D. a person who studies other people
Answer:
b, it's a pretty easy explanation