Answer:
First, as you may know, the light travels at a given velocity.
In vaccum, this velocity is c = 3x10^8 m/s.
And we know that:
distance = velocity*time
Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.
This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)
Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.
The astronomers could know what was happening inside galaxies way back then by the fact that;
they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find
Astronomers Measure the wavelength of the light that is stretched, so the light is seen as 'shifted' towards the red part of the spectrum by using spectroscopy. This measure is also called redshift.
This invokes a ray of light through a triangular prism that splits the light into various components known as spectrum.
The way the astronomers could use this concept to know what was happening in the galaxies before is by examining the spectra of galaxies that have the highest redshifts.
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Pls help! If you know the answer
Answer:
-40
Explanation:
-40= (9/5)(-40) + 32
=-72 + 32
-40=-40
Read the article, "Does Science Never Absolutely Prove Anything?" Then consider the theory of evolution. Do you consider the theory of evolution proven, evolving, or borderline science? Support your answer.
Answer:
Explanation:
Evolution/Advancement on the off chance that you see,then you will find this is a definitive revelation of science.It demonstrated that how people came into the world.How different creatures endure and from where they have hit on where they are today.All such things are the piece of development process.
New things advanced consistently from the past one and its a slow process.For anything to sprout you need a seed.As per the scientist,evolution is a reality and it is a steady procedure and it is happening.There are scarcely any situations where in the old harvest can yield new assortment as well.This is something many refer to as advancement only.Its a ceaseless process.Whatever comes,it accompanies certain misstep or zones of improvement,so if there happens to be a few changes would prompt improvement of new thing.
In the event that you see at an early stage,worms were available ,from where the fish came,then some went ahead land and began adjusting the progressions require to make due on land,started strolling on legs,developed lungs,then likewise there were advancement of the considerable number of things require to proceed with the life.All are the piece of development as it were.
hence,Darwin said,that natural selection can prompt evolution.This is likewise evident that so as to address the issue of food and nutrition,everybody works and as long as you get those needs,there will be development in all aspects.Similarly happened to the antiquated occasions when advancement occurred.
Hence,The development is truth and is a continuous procedure according to the science.When you go to demonstrate some case,there are consistently a point from where new methodology can be shaped and can prompt another disclosure.
If we consider the theory of evolution then we can say that it’s a proven theory, the reason people says that scientists don’t prove anything is because of the fact that they always implement “Precautionary principle” in their research finding.
Answer:
.
Explanation:
Una partícula se mueve en el plano XY efectúa un desplazamiento mientras actúa sobre ella una fuerza constante. X= (4i + 3j) m, F = (16i + 12j) N a) Calcule la magnitud del desplazamiento y la de la fuerza. B) Calcule el trabajo realizado por la fuerza F c) Calcule el ángulo entre F y x.
Answer:
a) La magnitud del desplazamiento es de 5 m
La magnitud de la fuerza es 20 N
b) El trabajo realizado por la fuerza es de 100 J
c) El ángulo entre la fuerza y el plano es 0 °
Explanation:
a) La magnitud del desplazamiento se encuentra por la relación;
[tex]\left | X \right | = \sqrt{X_{x}^{2}+X_{y}^{2}}[/tex]
Lo que da;
[tex]\left | X \right | = \sqrt{4^{2}+3^{2}} = 5 \ m[/tex]
De manera similar, la magnitud de la fuerza, F, se encuentra como sigue;
[tex]\left | F \right | = \sqrt{F_{x}^{2}+F_{y}^{2}}[/tex]
Lo que da;
[tex]\left | F \right | = \sqrt{16^{2}+12^{2}} = 20 \ N[/tex]
b) El trabajo, W, realizado por la fuerza = Fuerza, F × Distancia, X
∴ Ancho = 20 N × 5 m = 100 N · m = 100 J
c) La dirección de la fuerza viene dada por la siguiente fórmula;
[tex]tan^{-1} \left (\dfrac{F_y}{F_x} \right ) = tan^{-1} \left (\dfrac{12}{16} \right ) = 38.9^{\circ}[/tex]
La dirección del plano viene dada por la siguiente fórmula;
[tex]tan^{-1} \left (\dfrac{X_y}{X_x} \right ) = tan^{-1} \left (\dfrac{3}{4} \right ) = 38.9^{\circ}[/tex]
Por tanto, el ángulo entre la fuerza y el plano = 0 °
La fuerza actúa a lo largo del plano.
Match the words to the correct blanks in the sentences. Use each choice only once. a. The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by________. b. As a protostar shrinks in size, its central temperature rises along with its________. c. A star that has not yet finished forming is called a_______. d. A forming star spins more rapidly as it collapses because of conservation of________. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a________.A. thermal pressureB. angular momentumC. energy balanceD. degeneracy pressureE. brown dwarfF. gravitational equilibriumG. protostar
Answer:
The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____
Which statement best describes semi-conductors? Lack free electrons that can move to other atoms Electrons within their atoms are strongly held by the nuclei Most electrons within their atoms are paired Electricity can flow through it under special conditions
Answer:
Option D (Electricity can flow through it under special conditions ) seems to be the correct choice.
Explanation:
A semiconductor has become a crystal substance with improved electrochemical properties although the temperature is increased. That would be to say, it often functions as an insulating material rather than as a conductor or a circuit. Chemical solvents could perhaps greatly enhance its conducting capacity.Other options that are provided are not related to the given theory. So that the above would be the correct choice.
Statement "Lack free electrons that can move to other atoms " describe semi-conductor.
Properties of Semiconductor:A semiconductor is a type of crystalline solid that is halfway between a conductor and an insulator in terms of electrical conductivity. A semiconductor is conducting in nature because it has free electrons and holes.So that, Lack free electrons that can move to other atoms.Learn more about the Semiconductor here:
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the distance between two successive troughs of wave is 0.4m. If the frequency of the source is 825Hz, calculate the speed of the wave
Answer:
speed=330m/s
Explanation:
the speed of wave is given as
speed(meter per second) =frequency(hertz) * wavelength(meters)
so using the above formula we substitute the figures given in the question in the formula we get
speed = 0.4*825
speed =330m/s
note m/s is the si unit for speed which is read as meter per second
therefore speed =330m/s
In order to find the resultant of two vectors we must use the pythagoran therom, a +b2-2. Where the crepresents the resultant vector
Answer:
Furthermore, the Pythagorean theorem works when the two added vectors are at right angles to one another - such as for adding a north vector and an east vector.
A fire cracker is fired and it rises to a height of 1000 m. Find the velocity by which it was
released and the time taken by it to reach the highest point (take a = 10 m/s²).
Answer:
Explanation:it is too easy
what is the frequency and wavelength of a remote control? PLEASE HURRY
Answer:
940 nanometers wavelength, and about an 300 mHz - 400 gHz frequency
a uniform rod of length 1.5m is placed over a wedge at 0.5m from one end .a force of 100 N is applied at its one end near the wedge to keep it horizontal .find weight of rod and reaction of wedge
Explanation:
The rod is uniform, so the center of gravity is at the center, or 0.75 m from the end. The wedge is 0.5 m from the end, so the center is 0.25 m from the wedge.
Sum the torques about the wedge (it may help to draw a diagram first). Take counterclockwise to be positive.
∑τ = Iα
W (0.25 m) − (100 N) (0.50 m) = 0
W = 200 N
Sum the forces in the y direction.
∑F = ma
F − 100 N − 200 N = 0
F = 300 N
what energy is used when we drink a sip of juice?
Answer:
mechanical energy or chemical energy
does fire have ways to protect itself from changes in the environment
Answer:
I think no because the critical properties distinguishing life is adaptation to changing environment and self replication of the information encoding the life process. Fire does not change its process to adapt to its environment, e.g. moving toward more fuel or storing and conserving fuel when it is in short supply.
Hope this help you!:)
Starting from rest, two skaters push off against each other on smooth level ice, where friction is negligible. One is a woman and one is a man. The woman moves away with a velocity of 1.9 m/s relative to the ice. The mass of the woman is 46 kg, and the mass of the man is 88 kg. Assuming that the speed of light is 3.0 m/s, so that the relativistic momentum must be used, find the recoil velocity of the man relative to the ice.
Teenagers
when they should stop drinking.
A. tend to know
B. have difficulty bypowing
C. ignore
A vertical cylinder with a heavy piston contains air at 300 K. The initial pressure is 2.0 x 105 Pa and the initial volume is 0.35 m3 . Take the molar mass of air as 28.9 g/mol and assume Cv= 5 2R. (A) Find the specific heat of air at constant volume in units of J kg·K . (5 pts) (B) Calculate the mass of air in the cylinder. (5 pts) (C) Suppose the piston is fixed. Find the energy input required to raise the temperature to 700 K. (5 pts). (D) Assume again the conditions of the initial state and assume the piston is free to move. Find the energy input to raise the temperature to 700 K. (10 pts)
Find answers and explanations in the attachments
Answer:
Explanation:
) (C) Suppose the piston is fixed. Find the energy input required to raise the temperature to 700 K.
5. Which of the following is NOT a course goal?
For students to understand fitness principles
For students to establish a habit of physical activity
For students to do nothing
For students to enhance their level of physical fitness
Answer:
for students to do nothing
Explanation:
because doing nothing is not a course goal
is the body temperature of every person 37 degree Celsius. Why?
Answer:
Scientists have found the reason why our body temperature is 98.6°farehenheit (37°c). Apparently it's the perfect balance as it's warm enough to prevent fungal infection but not so hot that we need to eat nonstop to maintain our metabolism. ... So we know we need a higher body temperature to ward off fungal infection.
A physics student stands on a cliff overlooking a lake and decides to throw a softball to her friends in the water below. She throws the softball with a velocity of 23.5 m/s at an angle of 39.5∘ above the horizontal. When the softball leaves her hand, it is 11.5 m above the water. How far does the softball travel horizontally before it hits the water? Neglect any effects of air resistance when calculating the answer.
Answer:
66.86m
Explanation:
Velocity of ball thrown, u = 23.5 m/s
Initial height of the ball above the water, H = 11.5 m
Angle of projection, θ = 39.5°
Vertical components of veloclty = usinθ
Horizontal components of veloclty = ucosθ
The soft ball hits the water after time 't'
Considering the second equation of motion
S = ut + 1/2at^2........ 1
But since the ball went through motion under gravity ( free fall ) rather than linear motion, then equation 1 can be rewritten as:
H = ut +/- 1/2gt^2
H = - 11.5m
U = usinθ
θ = 39.5°
a = -g = -9.8m/s^2
- 11.5m = 23.5(sin39.5°)t + 1/2(-9.8)t^2
-11.5m = 23.5(0.6360)t - 4.9t^2
-11.5m = 14.946t - 4.9t^2
4.9t^2 -14.946t-11.5m = 0
Since the ball drifted horizontally
D = (Ucosθ)t
Where θ = 39.5°
U = 23.5m/s t=
Alternatively,
horizontal component of the velocity is 23.5 cos 39.5º = 18.1331 m/s
now how long does it take the ball to raise to a peak and fall to the water.
vertical component of velocity = 23.5 sin 39.5º = 14.947m/s
time to reach peak t = v/g = 11.947/9.8 = 1.5252 sec
peak reached above cliff top is
h = ½gt² = ½(9.8)(1.5252)²
= ½×22.797
= 11.3985m
now the ball has to fall 11.3985+ 11.5 = 22.8985m
time to fall from that height is
t = √(2h/g) = √(2• 22.8986/9.8) = 2.1617 sec
add up the two times to get time it is in the air, 2.1617 + 1.5252 = 3.6869
now haw far does the ball travel horizontally in that time
d = vt = 18.1331 ×3.6869= 66.856m
= 66.86m
The temperature of air changes from 0 to 10°C while its velocity changes from zero to a final velocity, and its elevation changes from zero to a final elevation. At which values of final air velocity and final elevation will the internal, kinetic, and potential energy changes be equal?
Answer:
Final velocity = 119.83 m/s
Final elevation = 731.9 m
Explanation:
We are told that temperature of air changes from 0 to 10°C
Thus;
Change in temperature; ΔT = 10 - 0 = 10°C
Also, its velocity changes from zero to a final velocity. Thus;
v1 = 0 m/s
v2 is unknown
Also, its elevation changes from zero to a final elevation.
So, z1 = 0 and z2 is unknown
Now, we want to find v2 and z2 when the internal, kinetic and potential energy are equal.
Thus Equating the formula for both kinetic and internal energy gives;
½m(v2² - v1²) = mc_v•ΔT
m will cancel out and v1 is zero to give;
v2² = 2c_v•ΔT
v2 = √(2c_v•ΔT)
Where c_v is specific heat of constant volume of air with a constant value of 718 J/Kg.K
Thus;
v2 = √(2 × 718 × 10)
v2 = √14360
v2 = 119.83 m/s
To find z2, we will equate potential energy formula to that of the internal energy.
Thus;
mg(z2 - z1) = mc_v•ΔT
m will cancel out and since z1 is zero, then we have;
z2 = (c_v•ΔT)/g
z2 = 718 × 10/9.81
z2 = 731.9 m
just want to double-check that you understand a practical consequence of the expansion of the universe. Light reaches us from a very distant galaxy. The time the light took to cross this distance and reach us is 10 billion years. The distance this light has crossed in this time is probably
Answer:
The distance of the light is 9.4608 x 10^25 m
Explanation:
Time taken by the light = 10 billion years = 10 x 10^9 years
speed of light = 3 x 10^8 m/s
speed of light in m/years is = (3 x 10^8)/(60 x 60 x 24 x 365) = 9.4608 x 10^15 m/year
distance = speed x time
therefore, the distance of this light = 10 x 10^9 x 9.461 x 10^15 = 9.4608 x 10^25 m
Answer:
more than 10 billion light years due to expansion of space
Explanation:
how many significant figures 216 m
Answer:
Three
Explanation:
I hope this helps:)
balloon moves backward when air rushes out of it why
Answer:
Because the air can move out of the balloon at such a speed, it propells the balloon forward.
Explanation:
SmolFox no longer exists
~Chad~
The action of the balloon pushes against the balloon moving it in the backward direction
What is newton's third law of motion ?Newton's third law of motion states that every action have a equal and opposite reaction . If object A exert force on object B , then object B will also exert an equal and opposite force on object A . Forces result from interaction of two bodies .
As we know according to Newton's third law of motion , when the air rushes out and pushes against the air which pushes the balloon to move in opposite direction , the action of the balloon pushes against the balloon moving it in the backward direction
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What is the centripetal acceleration of a point on the perimeter of a bicycle wheel diameter 70.0 cm when the bike is moving 8.0 m/s? (160 m/s)
It’s 180 m/s^2 dude. I think I have you in my class lol.
The centripetal acceleration of an object is due to the changing velocity in a circular path and the centripetal acceleration of the bicycle is 182.85 m/s².
What is Centripetal acceleration?Centripetal acceleration of an object can be defined as the property of the motion of an object which is traversing a circular path. Any object which is moving in a circular path and has an acceleration vector pointed towards the center of that circular path is known as Centripetal acceleration.
The centripetal acceleration of an object can be calculated by the formula:
ac = v²/ r
where, ac = centripetal acceleration,
v = velocity of the object,
r = radius of the circular path
The centripetal acceleration of the object will be:
ac = (8)²/ r
radius = diameter/ 2
radius = 70/ 2
radius = 35cm or 0.35 m
ac = 64/ 0.35
ac = 182.85 m/s²
Therefore, the centripetal acceleration of the bicycle will be 182.85 m/s².
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if you drop a rock with a density of 1.73 grams will it float or sink
Answer:
the rock will sink. this is because it is more dense than water
Answer:it will sink
Explanation:
because the density of water is 1g and the rock is heavier the the density of water
Which statement accurately describes dark matter?
Answer:
Dark matter is the term astronomers use to describe material in the universe that does not emit or reflect light and is, therefore, invisible.
Explanation:
Stars, nebulae, and galaxies are examples of luminous objects in the sky. However, luminous matter appears to make up only a small fraction of all the matter in the universe, perhaps only up to 10 percent.
Part B After producing electricity in many different ways, describe what causes electricity to flow in the coil? In your response, describe the types of forces acting on the electrons and how they result in movement.
Explanation:
If a coil of wire is placed in a changing magnetic field, a current will be induced in the wire. ... A changing magnetic field through a coil of wire therefore must induce an emf in the coil which in turn causes current to flow.
Due to the flow of the current run, the coil magnetic field is produced. Magnetic fields result in magnetic force.
What is electric force?The electric force between the two charges is directly propotional to the product of the charge and inversly propotional to the square of the distance between them.
A current will be generated in a wire coil if it is put in a changing magnetic field. As a result, a changing magnetic field through a coil of wire must create an emf in the coil, causing the current to flow.
A current is induced in a coil of wire when it is put in a changing magnetic field. Something generates an electric field that drives the charges around the wire, causing the current to flow.
Hence due to the flow of the current in the coil magnetic field is produced.
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List two factors that compression force depends on
The magnitude (size or numerical value) and the direction.
Hope this helps!!! :)
PLS HELP ME Define Derived Quantities ?
Derived Quantities
Explanation: Those physical quantities which are derived from fundamental quantities are called derived quantities and their units are called derived units. e.g., velocity, acceleration, force, work etc.
Answer:
These are quantities calculated from two or more measurements
Explanation:
They can't me measured directly.
They can only be computed.
They are calculated in PHYSICAL SCIENCE.
hope it helps.
7. Calculate the force applied on an object if the Pressure exerted is 90 Pascal over an area of 900 cm2.
Answer:
Explanation: pressure = force / area
Rearrange to get: force = pressure x area. 900 cm2 = 0.09 m2
force = 90 x 0.09
= 8.1 N
A body of mass m moves along y such that at time t its position is y(t)= at^2 – bt + c, where a, b, c are constant.
(a) Calculate the acceleration of the body. (b) What is the force acting on it?
Answer:
what do u need help with
Explanation:
A body of mass m moves along X-axis such that its position co-ordiante at any instant t is x = `at^(4)