Answer:
do your work why you in class and you would know
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.
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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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
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
5. The net external force on a rock of mass 4.2 kg is 8.0 N forward. Find the acceleration of the rock.
Answer:
1.904
Explanation:
F= ma
8 = 4.2 a
a = 8/4.2
a = 1.904
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 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).
Which event provides evidence that matter can reflect waves?
A. A dog's bark is barely heard through double-pane windows.
B. A bat finds a moth using echolocation.
C. A whale's song is heard hundreds of miles away,
D. A fish appears to be farther from a boat than it is.
Answer:
B. A bat finds a moth using echolocation
Explanation:
100% i just took that test today
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:
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
If work stays the same and the distance is increased, then less force is needed to do the work.
True
False
Answer:
False
Explanation:
This is because the work is the same so the force won't change
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.
What is the volume of 150g of a substance that has a density of 150g of a substance that has a density of 11.3g/cm3
Answer:
25.0 cm3
Explanation:
The volume is 25.0 cm3 .
Ryder is testing the change in motion for an object that weighs 25 kg and an object that weighs 30 kg. He will push each object with the same force. Ryder predicts the object that weighs 25 kg will have a greater change in motion. Is this correct?
Yes, the object with the smaller mass will have a greater change in motion.
No, the change in motion for both objects will be the same.
Yes, the mass is greater, and the object will have a greater change of motion.
No, neither of the objects will have a change in motion.
Ryder is testing the change in motion for an object that weighs 25 kg and an object that weighs 30 kg. Then, the greater change in motion is due to the greater mass of the object, and the object will have a greater change of motion. Thus, the correct option is C.
Motion is the phenomenon in which an object changes its position with respect to the time taken. Motion of an object is mathematically described in terms of the displacement covered by the object, the distance, velocity, acceleration, speed and the frame of reference to an observer and measurement of the change in the position of the body of an object relative to that particular frame with the change in time taken.
The motion of an object is proportional to the mass of the object. The mass is greater in this case, and therefore the objects will have a greater change of motion.
Therefore, the correct option is C.
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2.(01.01 LC)
Which of the following is true for gravitational force? (3 points)
Decreases with increase in mass
Increases with increase in mass
Increases with increase in distance
Decreases with decrease in distance
Answer:
Increases with increase in mass
Explanation:
gravity is proportional to mass and inversely proportional to the square of the distance between them
F = GMm/d²
What is friction ???
Answer:
Frictional force is produced when two bodies are rubbed against each other. It is the force that oppose the motion and therefore it stops or slow down a moving body.It depends upon the roughness or smoothness of the surface of the body in contact.Rough surface have more friction that the smooth surface. Similarly, the heavier body produces more friction than a lighter body. Frictional force acts in the opposite direction of the motion of the body.
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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does gravity cause a change in an objects movement
Answer:
yes
Explanation:
because gravity moves things
HIHIHHHHHHHHIHIHIIHIHHHHIHIHIHIHIHIHIHIHIHIHIHIHIHIIH
Answer:
Ok thanks for the points though
Explanation:
I will mark brainlist
If a wave’s amplitude is 2cm, then its height is equal to:
5 cm.
0 cm
4 cm.
2 cm
Answer:
4 cm
Explanation:
Amplitude is the measure from the MIDLINE to the peak of the wave....so the wave HEIGHT is twice the ampltude
2 x 2 cm = 4 cm
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.
9
are things that you can achieve quickly.
O A.
Dreams
OB.
Long-term goals
O c.
Short-term goals
OD.
Plans
Answer:
d
Explanation:
A dreams
.......wkkwkwkwkwkwnwnsksk
Answer:
C. short term goal
Explanation:
took a midterm quiz on canvas, Hope this helps <3
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:
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...
Please write a paragraph explaining the bible verse below in your own words.
Exodus 16:19-20
Answer:
Moses had told them to not keep the food till morning but some kept some anyways because they probably thought they were going to starve or not have food the next morning but what I think it means is that you have to trust in God that he will provide for you and so when the people kept the food cuz he thought they were probably going to start of the next day it got maggots
Example 4.16
An object of mass 3 kg rests on a plane. The coefficient of static friction and that of kinein
friction are given by Hs = 0.3 and pk = 0.2.
The plane is inclined at angle o to the horizontal.
(i) Find the maximum value of 0 for which the object remains at rest on the plane.
(ii) Find the acceleration of the object if it started sliding from rest down the plane at
angle Omax to the horizontal.
(ii) How long does it take the object to move, from rest, a distance of Imetre under the
conditions of (ii).
Answer:
Explanation:
(i) μs = F/N = mgsinθ/mgcosθ = tanθ
tanθ = 0.3
θ = 16.7°
(ii) a = F/m
a = (mgsinθ - (μk)mgcosθ) / m
a = g(sinθ - (μk)cosθ)
a = 9.8(sin16.7 - (0.2)cos16.7)
a = 0.94 m/s²
(iii) s = ½at²
t = √(2s/a)
t = √(2(1)/0.94)
t = 1.5 s
A 27 kg chair initially at rest on a horizontal
floor requires a 173 N horizontal force to set
it in motion. Once the chair is in motion, a
148 N horizontal force keeps it moving at a
constant velocity.
The acceleration of gravity is 9.81 m/s.
a) What is the coefficient of static friction
between the chair and the floor?
Answer:
4653
4565445655687568677667876
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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Why does the sky appear red and yellow during sunsets.
1. The reds and yellows are caused by the Sun's light having to pass through dust particles near closer to the horizon than when the Sun is higher in the sky.
2. At sunset the prismatic effect of the atmosphere at low angles produces longer red and yellow wavelengths.
3. At sunset blue light is scattered by air molecules at higher altitudes. The longer red and yellow wavelengths must travel further through the atmosphere when the Sun is near the horizon. At some point the reds and yellows finally scatter in the lower atmosphere causing the reds and yellows.
4. The red and yellows are appear at sunset because the light must pass through more atmosphere which slows down the wavelength frequency turning it to slower red and yellow frequencies.
Answer:
The answer should be 3-At sunset blue light is scattered by air molecules at higher altitudes. The longer red and yellow wavelengths must travel further through the atmosphere when the Sun is near the horizon. At some point the reds and yellows finally scatter in the lower atmosphere causing the reds and yellows.
Answer:
3. At sunset blue light is scattered by air molecules at higher altitudes. The longer red and yellow wavelengths must travel further through the atmosphere when the Sun is near the horizon. At some point the reds and yellows finally scatter in the lower atmosphere causing the reds and yellows.
Two students were climbing stairs at school. Student 1 has a weight of 700 N. Student 2 has a weight of 650 N. How much power would each student have if each took 6 s to climb a 4 m tall flight of stairs?
Student 1 would have 4200 W, and Student 2 would have 3900 W of power.
Student 1 would have 116 W, and Student 2 would have 108 W of power.
Student 1 would have 2800 W, and Student 2 would have 2600 W of power.
Student 1 would have 467 W, and Student 2 would have 433 W of power.
Student 1 would have a power 467 W and student 2 would have a power of 433 W. The correct option is the fourth option - Student 1 would have 467 W, and Student 2 would have 433 W of power.
From the question,
We are to calculate the power each student would have to climb the flight of stairs.
Power can be calculated using the formula
[tex]P = \frac{F \times d}{t}[/tex]
Where
P is Power
F is the force
d is the distance
and t is the time
NOTE: The weight of the students represent the force
For student 1F = 700 N
d = 4 m
t = 6 s
∴ [tex]P = \frac{700 \times 4}{6}[/tex]
P = 467 W
For student 2
F = 650 N
d = 4 m
t = 6 s
∴ [tex]P = \frac{650 \times 4}{6}[/tex]
P = 433 W
Hence, Student 1 would have a power 467 W and student 2 would have a power of 433 W. The correct option is the fourth option - Student 1 would have 467 W, and Student 2 would have 433 W of power.
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