Dark matter and dark energy described as dark because of its no interaction with electromagnetic field.
Why are dark matter and dark energy described as dark?
Dark matter is called "dark" because it does not interact with the electromagnetic field. This means that it does not absorb, reflect, or emit electromagnetic radiation and therefore, it is difficult to detect.
So we can conclude that dark matter and dark energy described as dark because of its no interaction with electromagnetic field like dark substances.
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Dark matter and dark energy are described as dark because it doesn't seem to interact with the electromagnetic field.
What is the matter?The matter is a material that fills space and has inertia. Modern physics states that matter is made up of several kinds of particles, each of which has a mass and size.
The electron, proton, and neutron are three of the most well-known instances of material particles. Atoms are made up of combinations of these particles.
Dark matter is so-called because it doesn't seem to interact with the electromagnetic field.
This means it doesn't generate electromagnetic radiation like light or absorb electromagnetic radiation as it does. As a result, it is hard to detect.
Hence, dark matter and dark energy are described as dark.
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4. An object is thrown from from the ground upward with an initial speed of 3.75 m/s. How long will the object be in the air before it lands on the ground?
Answer:
Explanation:
There's an easy way to answer this and then an easier way. I'll do both since I'm not sure what you're doing this for: physics or calculus. Calculus is the easier way, btw.
Going with the physics version first, here's what we know:
a = -9.8 m/s/s
v₀ = 3.75 m/s
t = ??
That's not a whole lot...at least not enough to directly solve the problem. What we have to remember here is that at the max height of a parabolic path, the final velocity is 0. So we can add that to our info:
v = 0 m/s. Use the one-dimensional equation that utilizes all that info and allows us to solve for time:
v = v₀ +at and filling in:
0 = 3.75 + (-9.8)t and
-3.75 = -9.8t so
t = .38 seconds. This is how long it takes to get to its max height. Another thing we need to remember (which is why calculus is so much easier!) is that at the halfway point of a parabolic path (the max height), the object has traveled half the time it takes to make the whole trip. In other words, if .38 is how long it takes to go halfway, then 2(.38) is how long the whole trip takes:
2(.38) = .76 seconds. Now onto the calculus way:
The position function is
[tex]s(t)=-4.9t^2+3.75t[/tex] The first derivative of this is the velocity function and, knowing that when the velocity is 0, the time is halfway gone, we will find the velocity function and then set it equal to 0 and solve for t:
v(t) = -9.8t + 3.75 and
0 = -9.8t + 3.75 and
-3.75 = -9.8t so
t = ,38 and multiply that by 2 to find the time the whole trip took:
2(.38) = .76 seconds.
Can somebody help me understand this
What is photosynthesis???
photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.[tex]\pmb{ }[/tex]
What is the name of the Egyptian sun god, usually depicted as a hawk-headed man with a solar disk and cobra on his head
Answer: Re-Horakhty
Explanation:
He has a human body and a falcon head, he has a crown in form of a disk with a cobra on his head. Ra-Horakhty was thought of as the god of the rising sun.
what is the angular speed w of the system immediately after the collision in terms f the sstem parameters and I
Answer: hello some part of your question is missing attached below is the missing detail
answer :
wf = M( v cos∅ )D / I
Explanation:
The Angular speed wf of the system after collision in terms of the system parameters and I can be expressed as
considering angular momentum conservation
Li = Lf
M( v cos∅ ) D = ( ML^2 / 3 + mD^2 ) wf
where ; ( ML^2 / 3 + mD^2 ) = I ( Inertia )
In terms of system parameters and I
wf = M( v cos∅ )D / I
Using diagram 1.1 and diagram 1.2, compare the number of turn of the coils, the pattern of the iron fillings and the angle of deflection of the ammeter pointer
Answer:
The number of turns in the second coil is more than the coil 1.
Explanation:
The magnetic field lines are the imaginary path on which an isolated north pole moves if it is free to do so.
The tangent at any point to the magnetic field line, gives the direction of magnetic field at that point.
More be the crowd ness of magnetic field lines more is the strength of magnetic field.
Here the crowd ness of magnetic field lines is more in figure 2 , so the magnetic filed in figure 2 is more than 1. It shows that the number of turns in the second coil is more than the 1 and also the current in the coil 2 is more than 1 .
Which best describes a molecule?
a unit made of different kinds of elements
a unit made of only one kind of element
a unit made of two or more atoms
a unit made of a single atom
A group of two or more atoms.
In one of the classic nuclear physics experiments at the beginning of the 20th century, an alpha particle was accelerated toward a gold nucleus, and its path was substantially deflected by the Coulomb interaction. If the energy of the doubly charged alpha nucleus was 2.25 MeV, how close (in m) to the gold nucleus (79 protons) could it come before being deflected
Answer:
The answer is "[tex]1.01 \times 10^{-13}[/tex]"
Explanation:
Using the law of conservation for energy. Equating the kinetic energy to the potential energy.
[tex]KE=U=\frac{kqq'}{r}\\\\[/tex]
Calculating the closest distance:
[tex]\to r=\frac{kqq'}{KE}\\\\[/tex]
[tex]=\frac{k(2e)(79e)}{KE}\\\\=\frac{k(2)(79)e^2}{KE}\\\\=\frac{9.0\times 10^9 \ N \cdot \frac{m^2}{c}(2)(79)(1.6 \times10^{-19} \ C)^2}{(2.25\ meV) (\frac{1.6 \times 10^{-13} \ J}{1 \ MeV})}\\\\[/tex]
[tex]=\frac{9.0\times 10^9 \times 2\times 79\times 1.6 \times10^{-19}\times 1.6 \times10^{-19} }{(2.25 \times 1.6 \times 10^{-13}) }\\\\=\frac{3,640.32\times 10^{-29}}{3.6 \times 10^{-13} }\\\\=\frac{3,640.32}{3.6} \times 10^{-16}\\\\=1011.2 \times 10^{-16}\\\\=1.01 \times 10^{-13}[/tex]
The most powerful empire between the 1500s and 1600s was the __________ Empire.
A.
Ottoman
B.
Mauryan
C.
Roman
D.
Persian
Answer:
A
Explanation:
Answer:
Ottoman
Explanation:
siri told me after I asked
The force that the left team pulls with is 1000 N. If the right team's total mass is 300 kg and they accelerate by 1.2 m/s2, what is the force of resistance on the right team
Answer:
the force of resistance on the right team is 360 N
Explanation:
Given;
force of the left team, = 1000 N
total mass of the right team, m = 300 kg
acceleration of the right team, a = 1.2 m/s²
The force of resistance of the right team is calculated as;
Force = mass x acceleration
Force, F = 300 x 1.2
Force = 360 N
Therefore, the force of resistance on the right team is 360 N
Classes. frequency
0-20 2
20-40. 2
40-60. 3
60-80 12
80-100 18
100-120 5
120-140. 2
Find mean, median and mode
Answer:
The mean is 79.[tex]\overline {54}[/tex]
The median is 80 - 100
The mode is 80 - 100
Explanation:
The given table is presented as follows;
[tex]\begin{array}{lcrc}Classes&Mid \ point &Frequency &Frequency \times Mid \ point\\0 - 20&10& 2&20\\20-40&30&2&60\\40-60&50&3&150\\60-80&70&12&840\\80-100&90&18&1620\\100-120&110&5&550\\120-140&130&2&260\end{array}[/tex]
The mean of a class of values, [tex]\overline x[/tex] = ∑(Frequency × Midpoint)/∑(Frequency)
Therefore, we get;
[tex]\overline x[/tex] = (20+60+150+840+1620+550+260)/(2+2+3+12+18+5+2) = 79.[tex]\overline {54}[/tex]
The mean, [tex]\overline x[/tex] =79.[tex]\overline {54}[/tex]
The median class = The middle value lass = The class at the 22 nd value = 80 - 100
The median = 80 - 100
The modal class = The class with the highest frequency = 80 - 100
The mode = 80 - 100
Find the transformation matrix that rotates a rectangular coordinate system through an angle of 60 about axes equal angels with original three coordinate axes
Answer:
[tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]
Explanation:
To find the matrix, let's decompose the vectors, the rotated angle is (-60C) for the prime system
x ’= x cos (-60)
y ’= y sin (-60)
we use
cos 60 = cos (-60)
sin 60 = - sin (-60)
we substitute
x ’= x cos 60
y ’= - y sin 60
the transformation system is
[tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right] = \left[\begin{array}{ccc}cos 60&0\\0&-sin60\end{array}\right] \ \left[\begin{array}{ccc}x\\y\end{array}\right][/tex]x '
the transformation matrix is
[tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]
In which region is there most likely to be a volcano
A
B
C
D
A 67.3-kg climber is scaling the vertical wall of a mountain. His safety rope is made of a material that, when stretched, behaves like a spring with a spring constant of 1.23 x 103 N/m. He accidentally slips and falls freely for 0.921 m before the rope runs out of slack. How much is the rope stretched when it breaks his fall and momentarily brings him to rest
Answer:
[tex]d=0.59m[/tex]
Explanation:
From the question we are told that:
Mass [tex]m=67.3 kg[/tex]
Spring constant [tex]\mu=1.23 * 10^3 N/m[/tex]
Fall Height [tex]h=0.921m[/tex]
Generally the Energy theorem equation for momentum is mathematically given by
Change in KE=Work done by gravity + work done by spring
[tex]0=mg*(h + d) - \frac{\mu d^2}{2}[/tex]
[tex]0=(67.3 * 9.81 (0.921 + d)) -\frac{(1.23 * 10^3 * d^2}{ 2}[/tex]
[tex]0=608.1-660.213d-615d^2[/tex]
Solving Quadratic equation
[tex]d=0.59m[/tex]
what is acceleration
[tex]\boxed{\large{\bold{\blue{ANSWER~:) }}}}[/tex]
[tex]\sf What \: is \: acceleration? \\ \\ \sf The \: rate \: of \: change \: of \: velocity \: of \: an \\ \sf object \: with \: respect \: to \: time \\ \sf is \: known \: as \: acceleration. [/tex]
what do you mean by time?
HOW OLD IS THE ISS? HOW LONG HAS IT BEEN OPERATIONAL?
Answer:
bhai nam kya hai (whats your name)
Explanation:
please comment
What do you think Jose’s grandmother meant by saying that the bread was too dense? What other things can you think of that are “dense”?
Answer:
What I think that Jose's grandmother meant by saying that the bread was too dense is that she thinks the bread is too heavy or it can even mean to be too compacted in substance. The matter in the bread are close together and not spread out like in the air, when the matter in the air starts to come closer together it starts to make fog, because it is becoming more dense. Some more things that are heavy or dense are things like a big stereo speaker, an anvil, or even a big piece of wood used to build.
Explanation:
!!!!!URGENT!!!!!!
A heater raises the temperature of air in a room from 22 °C to 37
°C with the energy of 7500 J. If the mass of the air is 5 kg, the specific heat
capacity of the air would be
A. 25 J kg^-1 °C^-1
B. 50 J kg^-1 °C^-1
C. 100 J kg^-1 °C^-1
D. 75 J kg^-1 °C^-1
Answer:
The specific heat of air is 100 J/kg°C.
Explanation:
mass, m = 5 kg
Temperature change, T' - T = 37 °C - 22 °C = 15°C
heat, H = 7500 J
let the specific heat of air is c.
The formula of heat is
H = m c (T' - T)
7500 = 5 x c x 15
c = 100 J/kg°C
Clothes are flung to the sides of a round tub during the spin-cycle of a washing machine.If the tub's period of rotation is 0.2s and the tub's radius is 35cm,answer the related qestions below: (a)The frequency of roation (b)The circumference of rotation (c)The spinning of speed (d)The centripetal acceleration (e)The centripetal force of rotation if total mass rotated is 30kg (f)The power of washing machine
Answer:
Explanation:
First I need to tell you that I used .20 s for the period of rotation instead of just .2, and I used 30.0 kg for the mass instead of just 30. The reason being that both those numbers as stated in the problem only have 1 significant digit and that's not generally enough to get the accuracy you're looking for. Adding a 0 to the ends of each of those numbers doesn't change the value of the numbers, only the number of sig fig's in each. Beginning with a:
a. [tex]f=\frac{1}{T}[/tex] so [tex]f=\frac{1}{.2}[/tex] and f = 5.0 Hz
b. The circumference is the distance around the outside of the washer's drum. We need to find that, but before we do, I'm going to state the radius in meters instead of cm. 35 cm = .35 m. Therefore,
C = 2(3.1415)(.35) so
C = d = 2.2 m
c. The speed of the washer is found in d = rt, where r is the rate and our velocity and d is the distance around the outside of the drum (circumference). Therefore,
2.2 = v(.20) so
v = 11 m/s
d. The centripetal acceleration has an equation
[tex]a_c=\frac{v^2}{r}[/tex] so
[tex]a_c=\frac{(11)^2}{.35}[/tex] and
[tex]a_c=\frac{121}{.35}[/tex] so
[tex]a_c=350\frac{m}{s^2}[/tex]
e. The centripetal force has an equation
[tex]F_c=\frac{mv^2}{r}[/tex] and
[tex]F_c=\frac{(30.0)(11)^2}{.35}[/tex] and
[tex]F_c=[/tex] 1.0 × 10⁴ N
f. The equation for Power is
[tex]P=\frac{W}{t}[/tex] where W is work and W = FΔx (force times displacement). Therefore,
[tex]P=\frac{(1.0*10^4)(2.2)}{.20}[/tex] so
P = 1.1 × 10⁵ Watts
Which statement best describes how pigments affect what colors humans
see?
Answer:
the component of light reflected by that object
Explanation:
Compared to the inertia of a 1-kilogram mass, the inertia of a 4-kilogram mass is
Explanation:
The inertia of a 4 kg mass is four times as great as a 1 kg mass.
While using a digital radiography system, suppose a radiographer uses exposure factors of 10 mAs and 70 kVp with an 8:1 grid for an AP shoulder radiograph with acceptable anatomical part penetration and detector element (DEL) exposure. If the radiographer desires to increase scatter absorption using a 12:1 grid, what new exposure factors should be used to maintain the same DEL exposure
Answer:
b. 12.5 mAs, 70 kVp
Explanation:
The given parameter are;
The initial exposure factors := 10 mAs and 70 kVp
The initial Grid Ratio, G.R.₁ = 8:1
The Grid Ratio with which the radiographer desires to increase the scatter absorption, G.R.₂ = 12:1
Given that the lead content in the 12:1 grid, is higher than the lead content in 8:1 grid and that 12:1 grid needs more mAs to compensate, and provides a higher image contrast, the amount of extra mAs is given by the Grid Conversion Factors, GCF, as follows;
The GCF for G.R. 8:1 = 4
The GCF for G.R. 12:1 = 5
Therefore, given that the mAs used by the radiographer for 8:1 Grid Ratio is 10 mAs, the mAs required for a G.R. of 12:1 in order to maintain the same exposure is given as follows;
mAs for G.R. of 12:1 = 10 mAs × 5/4 = 12.5 mAs
Therefore the new exposure factors are;
12.5 mAs, 70 kVp
A jet plane lands at a speed of 100 m/s and can accelerate at a maximum rate of -5.00 m/s^2 as it comes to a rest.
(a from the instant the plane touches the runaway, what is the minimum time needed before it can come to a rest?
(b Can this plane land on a runaway that is only 0.800 km long?
shown work pls will reward alot of points
Answer:
a) t = 20 s, b) x = 1000 m, As the runway is only 800 m long, the plane cannot land at this distance
Explanation:
This is a kinematics exercise
a) in minimum time to stop,
v = vo + at
v = 0
t = -v0 / a
we calculate
t = -100 / (5.00)
t = 20 s
b) Let's find the length you need to stop
v² = vo² + 2 a x
x = -v0 ^ 2 / 2a
x = - 100² / 2 (-5.00)
x = 1000 m
As the runway is only 800 m long, the plane cannot land at this distance.
: Một mặt phẳng vô hạn tích điện đều, mật độ σ = 4.10-9 C/cm2, đặt thẳng đứng trong không khí. Một quả cầu nhỏ có khối lượng 8 g, mang điện tích q = 10-8 C treo gần vào mặt phẳng, sao cho dây treo lúc đầu song song với mặt phẳng. Lấy g = 9,8m/s2. Khi cân bằng, dây treo quả cầu hợp với mặt phẳng 1 góc bằng bao nhiêu?
Answer:
The angle is 16 degree.
Explanation:
A uniformly charged infinite plane, density σ = 4.10-9 C/cm2, is placed vertically in air. A small ball of mass 8 g, with charge q = 10-8 C, hangs close to the plane, so that the string is initially parallel to the plane. Take g = 9.8m/s2 . In equilibrium, by what angle does the string hanging from the ball make an angle with the plane?
Surface charge density, σ = 4 x 10^-9 C/m^2
charge, q = 10^-8 C
mass, m = 0.008 kg
Let the tension is the string is T and the angle is A.
[tex]T sin A = q E....(1)\\\\T cos A = m g .... (2)\\\\Divie (1) by (2)\\\\tan A =\frac{q E}{m g}\\\\tan A = \frac{10^{-8}\times 4\times 10^{-5}}{2\times 8.85\times 10^{-12}\times 0.008\times9.8}\\\\tan A = 0.288\\\\A = 16 degree[/tex]
What is the current flowing through the circuit shown? (V= 110 V, R, = 200, R2 = 300, R3 = 10 0) (Ohm's law: V = IR)
A. 1.8 A
B. 20 A
C. 0.05 A
D. 0.55 A
Answer:
A
Explanation:
The first thing you have to do is go back and list the resistances correctly. R1 = 20 R2 = 30 and R3 = 10.
Leave the units off if you can't make an omega.
The resistance of a series circuit (that's what this is) is r1 + r2 + r3 = 10 + 20 + 30 = 60 ohms
Now use ohms law.
R = 60 ohms
V = 110 volts.
I = V / R
I = 110/60
I = 1.833 to the nearest 1/10 = 1.8
What kind of waves are present during an earthquake?
Answer:
There are four main types of earthquake waves:
P-waves S-waves (which are body waves), Rayleigh waves Love waves (which are surface waves).HOPE IT HELPS!!
The 75.0 kg hero of a movie is pulled upward at a constant velocity by a rope. What is the tension on the rope?
Answer:
750 N
Explanation:
the tension on the rope is the weight of the hero
how to answer thiss helppp
Answer:
Look at work
Explanation:
Your given the mass of planet M and radius as well as second mass.
Use universal gravitation law to find force of gravity
Fg= Gm1m2/r^2
Plug in givens
Fg= 553.6 N
Use newtons second law
Fg= ma
553.6N=5a
solve for a= 110.72m/s
Weight is 553.6N
Try working backward from the desired goal to the starting point or current state. This advice describes a
Answer:
heuristic.
Explanation:
Psychology can be defined as the scientific study of both the consciousness and unconsciousness of the human mind such as feelings, emotions and thoughts, so as to understand how it functions and affect human behaviors in contextual terms.
This ultimately implies that, psychology focuses on studying behaviors and the mind that controls it.
A heuristic is an automatic mental shortcut or rule of thumb that avail people the opportunity to make quick and efficient judgement in decision-making process, as well as proffering solutions to a problem. Thus, it allows people to make decisions, pass probability judgement or proffer solutions to problem quickly and efficiently while applying minimal mental effort.
Basically, a heuristic helps an individual to shorten the decision-making time while paying less attention on thinking of his or her next course of action.
Hence, when you're advised to try working backward from the desired goal to the starting point or current state. This advice describes a heuristic.
