Explanation:
In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium in which they are propagated and the mass per unit volume of the medium (that is:density).
In other words: The speed of sound varies depending on the medium through which the sound waves travel.
So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.
Hence, the correct option is: an underground lake.
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Briefly describe what you think the world would be like if the amount of greenhouse gases in the atmosphere were reduced to levels like those during the ice age.
Answer:
If they were reduced to the levels like those during the ice ages, I think the Earth might go back to being frozen again.
Right now, what make the glaciers and polar ice caps melt?
Global Warming and greenhouse gases are depleting the Ozone. The Ozone is what traps the heat from the Sun and radiates it back to the Sun. Greenhouse gas is depleting the Ozone, which means that the heat from the sun is less protected, which results in climate change. It makes the Earth hotter which can mean that the glaciers are melting because the climate in the North and South pole is way to hot for it to stay frozen.
Hope this helped!
Answer: Earth would become frozen and also greenhouse gases reduce the ozone layer which is why glaciers are melting and Earth is getting hotter. It is why greenhouse gases are a big issue.
what are igneous intrusions and extrusions
Igneous intrusions form when magma cools and solidifies before it can reach the surface. An extrusion consists of extrusive rock; which forms above the surface of the crust.
5. An 8 kg shopping cart is pushed, causing it to accelerate by 4 m/s? How much force was used to
push the cart? Use the equation below to calculate the answer.
Answer:
Force will be 32N
Explanation:
The equation used is F = ma where m is mass and a is acc.. We just multiply mass( in Kg as Kg is SI unit )by acc. and get the force required .
A hot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. After it is released, the sandbag encounters no appreciable air drag. Compute the velocity of the sandbag at 0.250 s after its release.
Answer:
[tex]v = 2.55\ m / s[/tex] ↑ upwards
Explanation:
Take the direction up (where the hot-air balloonist moves) as the positive direction, and take the direction down (contrary to the direction of the hot-air balloonist) as the negative direction.
Then we propose the kinematic equation for the speed of the sandbag:
[tex]v (t) = v_0 + at[/tex].
Where
[tex]v_0[/tex] is the initial velocity of the sandbag
a is the acceleration of the sandbag
t is the time in seconds.
In this case
a is the gravitational acceleration of [tex]9.8\ m / s ^ 2[/tex]
[tex]v_0 = 5\ m / s[/tex]
[tex]t = 0.250\ s[/tex]
Now we substitute these values into the formula and solve for [tex]v(t)[/tex]
[tex]v = 5 + (-9.8) (0.250)\\\\v = 5 -9.8 (0.250)\\\\[/tex]
[tex]v = 2.55\ m / s[/tex] ↑ upwards
A 1,200 kg car is accelerated at 3.7 m/s2. What force was needed to produce this acceleration?
A.
4,440 N
B.
324.3 N
C.
4,388 N
D.
304.3 N
Answer:
A. 4,440 N
Explanation:
A Force applied on an object with mass 'm' can change its velocity in a unit time. This change is called acceleration.
If a force 'F' is applied on a body of mass 'm', it produces an acceleration 'a' in the body.
Force is give as :
F = ma
In our case,
m = 1200 kg a = 3.7 m/s²
F = 1200 x 3.7
F = 4440 kgm/s²
F = 4440 N
what is light intensity?
Light intensity is the "amount of light given off a light source." Also, is the measure the wavelength of the amount of light given off by a light source.
Hope this helps.
It's the brightness of something, and is measured as the rate at which light energy is delivered to a unit of surface, or energy per unit time per unit area.
kyle is swinging at the playground. as he moves from the top of the swing to the bottom he will _____.
a. gain potential energy and lose kinetic energy
b. lose potential energy and gain kinetic energy
c. change potential energy into mechanical energy
d. change kinetic energy into mechanical energy
need help ASAP!!
Answer:
a. gain potential energy and lose kinetic energy
Explanation:
Answer: gains potential and lose kinetic energy
Explanation:
The melting point of ice is the same temperature as the of water.
Answer:
Answer is freezing point of water. The same melting point of ice is the same freezing point of water.
Answer:
Freezing point.
Explanation:
In the case of freezing point and melting point there is a same transition of matter. In this case, freezing point is defined as the, liquid is changing into solid and this process will occur at the same temperature when melting is occur means solid is change into liquid.
When water is freezing or melting any one can notice that its temperature will remain at 0°C throughout these processes whether ice is converting into liquid or liquid is converting into ice.
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The Doppler effect indicates that the universe is expanding because_________.
A) light from other galaxies is the same color
B) light from other galaxies is different colors
C) light from other galaxies is blue shifted
D) light from other galaxies is red shifted
Answer:
D) light from other galaxies is red shifted
Explanation:
The Doppler effect indicates that the universe is expanding because light from other galaxies is red shifted.
Hope this helps!
I took the test.
The combining of light nuclei is called blank. Blank as in ____. Not actually blank. You know what im tryin to say.
Answer:
The combining of light nuclei is called nuclear fusion.
Answer:
Fusion
Explanation:
The combination of two lighter nuclie and forms a new heavier nucleus and release and lot of amount of energy is called nuclear fusion.
To start the nuclear fusion reaction we need a very high temperature.
We get energy from sun, it is due to the nuclear fusion of hydrogen and forms helium.
A wave is produced in a rope. The wave has a speed of 33 m/s and a frequency of 22 Hz.
What wavelength is produced?
a 2.35 water bucket is swung in a full cirlce of radius 0.824 m just fast enough so that the water doesn't fall out the top meaning n equals zero there. What is the speed of the water at the top
Answer:
2.84 m/s
Explanation:
At the top position of the circular trajectory, the normal reaction is zero:
N = 0
So it means that the only force that is providing the centripetal force is the gravitational force (the weight of the bucket). Therefore we have:
[tex]mg = m \frac{v^2}{r}[/tex]
where
m is the mass of the water bucket
g = 9.8 m/s^2 is the acceleration of gravity
v is the speed of the bucket
r = 0.824 m is the radius of the circle
Solving for v,
[tex]v=\sqrt{gr}=\sqrt{(9.8 m/s^2)(0.824 m)}=2.84 m/s[/tex]
Which device uses AC current to operate?
Answer:
the items you connect to a household outlet.
Explanation:
There exists many devices that uses AC current to operate. For example:
1. Electric Clocks. Synchronous clocks rely on the 50 or 60 Hz utility frequency of the AC electric power grid as a timing source. There are cases in which Power Plants decreases its frequency (Most of the times because of a failure), and for that reason you will find that electric clocks are delayed.
2. Fridge. Yes, your fridge needs AC current to work, that's why it's connected to your outlet!
3. Microwave. Yes, also your microwave needs AC current to work.
Basically, all of the items you connect to an outlet works with AC current.
Describe uniform velocity and variable velocity in short
Answer:
If the an object is moving in such a way that the magnitude of its velocity is same but its direction is changing then the object is said to be moving with variable velocity. Uniform velocity is when an object has an equal distance and an equal interval of time in a specific direction it is said to have uniform velocity.
What is the Coriolis effect and doppler effect in detail. Tell me about both. Will give brainliest and lots of points
Answer:
The Coriolis effect is basically Earth's rotation, the Doppler effect is the change in frequency or wavelength of a wave.
Which is not a source of noise pollution?
A)airplanes
B)acid rain
C)machines
D)cars
Answer:
acid rain.
Explanation:
its kinda obvious.
Is a cremated flower pot a good conductor? please help.
Answer:
It depends on the size and density but No.
Explanation:
Which units can be used to measure length or distance? Check all that apply.
gram
meter
kilometer
liter
inch
Answer:
meter
kilometer
inch
Explanation:
The units can be used to measure length or distance are meter, kilometer and inch.
What is length?Length is the distance measured from one point to the the other.
Length is the fundamental unit of the physical system. It can be expressed in different units systems like SI, FPS or CGS
Thus, the units used to measure distance are meter, kilometer and inch.
Learn more about length.
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what are the characteristic of a magnet
Answer:
They seek the path of lease resistance between opposite magnetic poles, in a single bar magnet they attempt to form closed loops from pole to pole and never cross each other.
ALWAYS use significant figure rules. Remember that these rules apply to all numbers that are measurements.
Calculate the force at sea level that a boy of mass 40 kg exerts on a chair in which he is sitting.
________ N
A. 390
B. 40.
C. 4
The force at sea level that a boy of mass 40 kg exerts on a chair in which he is sitting is 390 N.
How to calculate the force?Mass of the boy = 40 kg.The direction of that force is always vertically downward.At sea level,
The acceleration due to gravity g[tex]= 9.8 m/s^2[/tex]Then the weight of the boy is the mass of the body itself.m = 40 kg.
Therefore,
w = [tex]40 kg *9.8 m/s^[/tex]
=392 N kg
= 392 N
392N means approximately 390 N.
Hence, the force at sea level that a boy of mass 40 kg exerts on a chair in which he is sitting is 390 N.
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Final answer:
To calculate the force exerted by a 40 kg boy sitting on a chair at sea level, multiply the boy's mass by the acceleration due to gravity (9.80 m/s²) to get 392 N, which is rounded to 390 N, following significant figure rules.
Explanation:
Calculating Force at Sea Level
To calculate the force at sea level that a boy of mass 40 kg exerts on a chair in which he is sitting, we apply Newton's second law of motion. Since we are considering his weight (the force due to gravity), the acceleration in this case is due to Earth's gravity, which is approximately 9.80 m/s². Therefore, the formula to calculate the force (F) is:
F = m x g
Where:
m is the mass of the boy and is given as 40 kg.
g is the acceleration due to gravity and is 9.80 m/s².
Now, we calculate the force:
F = 40 kg x 9.80 m/s² = 392 N.
Following significant figure rules, we round our answer to 2 significant figures because the mass was provided to 2 significant figures. Thus, our final answer is:390 N
a force of 1 Newton is equivalent to 1
A force of 1 Newton is equivalent to 1 kg (m/s²). The product of mass and acceleration is known as force.
What is force?Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
Force is defined as the product of mass and acceleration. Its unit is Newton.
F=ma
The Si unit of the force is Newton. While the MKS unit is found as;
F=ma
F = kg (m/s²)
Hence, a force of 1 Newton is equivalent to 1 kg (m/s²).
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In which situation is no work being done?
A. a person carrying a box from one place to another
B. a person picking up a box from the ground
C. a person pushing a box from one place to another
D. a person pulling a box from one place to another
In physics, 'work' is a force causing the motion of an object. For work to be done, there must be displacement in the direction of the applied force. In the scenario presented, the situation in which no work is done is when a person is carrying a box from one place to another, as the force and displacement are perpendicular to each other.
Explanation:The concept of 'work' in physics is different from the everyday usage of the term. In physics, work is defined as a force causing the motion—or displacement—of an object. In the concept of work, two key components need to be present: force and displacement in the direction of the force.
With this definition, the scenario where no work is being done is: A. a person carrying a box from one place to another. In this situation, regardless of the weight of the box, if the person carries it horizontally, the force exerted (which is vertically upwards, opposing the weight of the box) and the displacement of the box (which is horizontal) are perpendicular to each other. Since work done is the product of force, displacement, and the cosine of the angle between them, when force and displacement are at 90 degrees, the cosine of the angle is zero and the work done is zero.
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please help!! 16 points !!!
Hey!
--------------------------------------------------
[tex]\Large\boxed{\mathsf{Option~D}}[/tex]
We can automatically eliminate option A and C because finding fossils isn't just trying to find the evolution of whales or bird. Archaeologists use fossils to see how animal evolve over a certain period of time. While they can build animals will the fossils they find but that isn't the most important use of fossils.
--------------------------------------------------
[tex]\Large\boxed{\mathsf{Option~A}}[/tex]
Typically scientists you radioactive dating to find how old a fossil. In this case that isn't an option. I chose option A because scientists can use shape of the fossil to determine what species its from and what part of the body it is.
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Hope This Helped! Good Luck!
What color of light must blue light mix with to create white light?
a.
yellow
b.
white
c.
blue
d.
green
According to the additive theory of color, when we join the three primary colors of light (Red + Green + Blue) we get White light.
On the other hand we have secondary colors of light that are:
Yellow = Red + Green
Magenta = Blue + Red
Cyan = Blue + Green
Now, if we know that:
Red + Green + Blue = White
And:
Red + Green = Yellow
Then:
Yellow + Blue = White
A systematic approach to problem solving is called a (an)
Answer:
An orderly, systematic approach to problem solving is called the. Scientific method.
"Scientific method" would be the systematic approach to solve the problems.
The concepts, as well as techniques for organizational knowledge development or exploration, include the identification but also the articulation of a challenge, which is considered as the Scientific method.Observation collecting via inspection as well as experimentation, as well as the creation and also verification of hypotheses.
Thus the response above is correct.
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Why is the question correct
Answer:
Sometimes the correct answer is there, as is, but the test has a different answer. Tell the teacher that the computer had the wrong answer.
A corporation gives out its profits as dividends paid to whom?
Answer: Stockholders
Explanation: stockholders
A corporation gives out its profits as dividends paid to its shareholders.
Who are shareholders?Individuals or organizations that have made financial investments in a firm by purchasing its shares or stocks are referred to as shareholders. When a company makes a profit, it has the option of keeping those earnings in the company for use in future investments or paying those profits out to shareholders in the form of dividends.
The payment of dividends typically takes the form of cash, but they may also be distributed in the form of extra shares of stock or property. The number of shares a shareholder owns in conjunction with the dividend policy of the company determines the amount of dividend money that shareholder receives. One method by which a company can show appreciation to its shareholders for the money they have invested and maintain their support is through the distribution of dividends.
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what is the best hypothesis to use for this investigation
Answer:
NOT:
If copper is a better conductor, it will heat up faster than iron.
Explanation:
what is meant by the statement" the melting poin of glycerine is 13 degree celsius
Answer:
This means the temperature at which glycerine changes from solid to liquid is 13 degrees Celsius.
Explanation:
Melting point of a substance is the temperature at which it changes from the solid state to liquid state. Heat breaks the intermolecular forces of attractions that holds the substance together.The solid and liquid state are in equilibrium at the melting point. The melting point of a substance depends on pressure, shape of the substance, etc.
The melting point of glycerine at 13 degrees Celsius signifies the temperature at which it changes from solid to liquid at standard atmospheric pressure.
When the statement "the melting point of glycerine is 13 degrees Celsius" is mentioned, it's describing the temperature at which glycerine transitions from a solid to a liquid state under normal atmospheric pressure.
Unlike the triple point, which is the specific temperature and pressure at which a substance's solid, liquid, and gas phases coexist in equilibrium, the melting point is simply the temperature at which the solid and liquid phases are in equilibrium at 1 atm pressure.
For instance, the triple point of water is a more precise calibration temperature than its melting point because it is not influenced by pressure.
In which situation will the lowest resistance occur?
Answer:
thick wire and cold temperatures
Answer: There may be two types of resistances here:
Air resistance: for example when something is falling down, the air will push the object upwards. As a bigger surface has the object, more air is pushing, so if you want to reduce the resistance yo must reduce the surface area. For example, a sheet of paper will experience more resistance if it is open if you make a small ball with it.
Electric resistance: This is the resistance of conductors against the electrons that try to travel along with it.
there are two equations here.
R = p*L/A, this talks about the volume and density of the conductor, where p is the density, L is the length and A is the area perpendicular to the direction in which the electricity flows.
Then if you reduce the length, and increase the area, the resistance will be reduced.
the other equation is: R(T) = R0( 1 + a*(T - 20°))
Where R0 is the resistance at 20° and a is a coefficient for T = 20°.
Here, you can see that at smaller temperatures, the resistance decreases, so we can conclude that we must increase the area, and decrease the length and temperature.