I don’t understand this

Answer:

Molecular scale. The story begins a long time ago  

when the idea that molecules are in constant motion  

was first discovered. Part of the evidence that you can  

see in everyday life was discovered by Robert Brown  

about 150 years ago when he used a microscope to  

watch how tiny dust particles move.

So how fast do molecules move? It all depends upon  

the molecule and its state: molecules in a solid state  

move slower than in a liquid state, and much slower  

than gas molecules. One estimate puts gas molecules  

in the range of 1,100 mph at room temperature. Cool  

them down to almost absolute zero and they slow  

down to less than 0.1 mph (slower than the average  

couch potato). The fact that they are always moving  

makes it a challenge to see molecules and make stuff  

out of them, but it’s a challenge that scientists  

work hard to figure out.

Explanation:

Answer:

83.09 J

Explanation:

The potential energy at the point of the top of the jump is represented by the equation

[tex]mgdeltah[/tex]

when the dog jumps, all the potential energy converts to kinetic energy (1/2mv^2). Plugging in the values:

(7.7)(4.184)(1.1) = 83.0907 J

Answer:

r =[tex]\frac{ 1 \pm \sqrt{ \frac{m}{M} } }{1 - \frac{m}{M} }[/tex]

Explanation:

Let's apply the universal gravitation law to the body (c), we use the indications 1 for the planet and 2 for the moon

          ∑ F = 0

           -F_{1c} + F_{2c} = 0

             F_{1c} = F_{2c}

let's write the force equations

             [tex]G \frac{m_c M}{r^2} = G \frac{m_c m}{(d-r)^2}[/tex]

where d is the distance between the planet and the moon.

              [tex]\frac{M}{r^2} = \frac{m}{(d-r)^2}[/tex]

             (d-r)² = [tex]\frac{m}{M} \ \ r^2[/tex]  

              d² - 2rd + r² = \frac{m}{M} \ \ r^2

              d² - 2rd + r² (1 - [tex]\frac{m}{M}[/tex]) = 0

              (1 - [tex]\frac{m}{M}[/tex])  r² - 2d r + d² = 0

we solve the second degree equation

              r = [2d ± [tex]\sqrt{ 4d^2 - 4 ( 1 - \frac{m}{M} ) }[/tex] ] / 2 (1- [tex]\frac{m}{M}[/tex])

              r = [2d ±  2d [tex]\sqrt{ \frac{m}{M} }[/tex]] / 2d (1- [tex]\frac{m}{M}[/tex])

              r =[tex]\frac{ 1 \pm \sqrt{ \frac{m}{M} } }{1 - \frac{m}{M} }[/tex]

there are two points for which the gravitational force is zero

The distance between object from planet will be "[tex]\frac{R}{[1+\sqrt{\frac{m}{M} } ]}[/tex]".

According to the question,

Let,

As we know,

→ [tex]Prerequisites-Gravitational \ force = \frac{GMm}{r^2}[/tex]

Now,

→ [tex]\frac{GMm_1}{x^2} = \frac{Gmm_1}{(R-x)^2}[/tex]

→ [tex]\frac{(R-x)^2}{x^2} = \frac{m}{M}[/tex]

→     [tex]\frac{R-x}{x} =\sqrt{\frac{m}{M} }[/tex]

→          [tex]x = \frac{R}{[1+ \sqrt{\frac{m}{M} } ]}[/tex]

Thus the answer above is appropriate.          

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Answer:

0.002 m/s

Explanation:

27.13(60) = 1,627.8 seconds

3.12/1,627.8 = 0.00191 ≈ 0.002 = s

Are you sure you're not looking for cm/s?

Answer:

Δx = distance between central bright fringe and first bright fringe = 19.85 x 10⁻⁴ m = 1.985 mm

distance between central bright fringe and second dark fringe = 2.978 mm

Explanation:

We have the following data:

λ = wavelength of light = 641 nm = 6.41 x 10⁷ m

L = Distance of Screen from slits = 3.19 m

d = slit separation = 1.03 mm = 1.03 x 10⁻³ m

Δx = distance between consecutive bright fringes = fringe spacing = ?

Using formula:

[tex]\Delta x = \frac{\lambda L}{d}\\\\\Delta x = \frac{(6.41\ x\ 10^{-7}\ m)(3.19\ m)}{1.03\ x\ 10^{-3}\ m}[/tex]

Δx = distance between central bright fringe and first bright fringe = 19.85 x 10⁻⁴ m = 1.985 mm

distance between central bright fringe and second dark fringe = 1.5Δx

distance between central bright fringe and second dark fringe = (1.5)(1.985 mm)

distance between central bright fringe and second dark fringe = 2.978 mm

Answer:

According to "http://ww2010.atmos.uiuc.edu"  Diffraction is the slight bending of light as it passes around the edge of an object.

Some examples of Light Defraction would be..

-CD reflecting rainbow colours

-Sun appears red during sunset

-From the shadow of an object

Answer:

es la 2

Explanation:

epero que te curva

Rhodium (Rh) is in period 5 on the periodic table. What does this tell you about this element ?

option - D

It has 5 energy levels/shells in its electron cloud.

With the information from the periodic table we can find that the correct statement is:

D. it is 5 energy level

The periodic table of the elements is a method of classifying the chemical elements based on their atomic number, it is divided into rows and columns

The rows are called the period and indicate the energy shell that is filled with electrons, all periods start with one electron and end when the shell is filled with 8 electrons.

The columns called groups correspond to elements that have the same number of electrons in their last shell, the chemical properties of the elements of the group are similar.

In this case we have an element the Rhodium, from period 5 and group VIIIB, when reviewing the period table it can be indicated that it has properties similar to cobalt and the inner layer is filled with two electors in its last layer.

When reviewing the different claims

a) False. The periodic table is not about molecules but about atoms

b) False. The metallic characteristics depend on the relationship between the number of electrons and the fermi level that is not indicated in the periodic table.

c) False. The number of protons is equal to the atomic number, in this case the rhodium has Z = 45, therefore it has 45 protons in the nucleus

d) True. It is at level 5 since the energy levels and the periods coincide.

In conclusion, with the information from the periodic table, we can find that the correct statement is:

D.  it is 5 energy level

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Answer:

Resistance is quadrupled.

Explanation:

Solving this requires us to use the formula of resistivity.

Resistivity is usually said to be the measure of the resistance of a particular size of any given material to the electrical conduction. It is mathematically represented as

ρ = RA/L, where

ρ = the resistivity of the given material

R = the resistance of the material

A = the area of the material

L = length of the material.

From the question, we're told that the length is doubled with the resistivity and density remaining constant. If the density is constant, this makes the volume constant as well.

Volume, V = A * L. We're then told that the length is doubled. If the length is doubled, for the volume to remain constant, then the area must be halved.

Volume, V = A/2 * 2L

Making, Resistance R, subject of the formula, we have

R = ρL/A.

Since resistivity is constant and the area is halved, we then have

R = 2L / (1/2A)

R = 4L / A

If the length is doubled, we have the resistance to be quadrupled

Answer:

Static electricity : is a familiar electric phenomenon in which charged particles are transferred from one body to another

Ohm's law : states that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance

Answer:

a new chromebook for you and you will get to know the other one that

Answer:

Conduction is the transfer of thermal energy through direct contact between particles of a substance, without moving the particles to a new location. Usually occurs in solids. When heat is supplied to one end, molecules at that end start to move more quickly.

Explanation:

Conduction is the transfer of heat and electricity through a material or surface. Generally, metals are good conductors of heat and electricity.

Conduction is the process through which heat energy is transmitted through the collisions which occur between neighboring atoms or molecules in a system. Conduction occurs more readily in the solids and liquid substances, where the particles are closer together than that of the gases, where the particles are further apart from each other.

Metals are good conductors of heat and electricity as they contain valence electrons and charge whereas non-metals are bad or poor conductors of heat and electricity as these elements does not contain valence electrons.

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Answer:

A. force

Explanation:

Magnetism is a type of force.

Answer:

A. force

Hope this helps

Answer:

Pressure is the perpendicular force applied per unit area.

Explanation:

Given that,

The mass of rock, m = 2.35-kg

It was released from rest at a height of 21.4 m.

(a) The kinetic energy is given by : [tex]E_k=\dfrac{1}{2}mv^2[/tex]

As the rock was at rest initially, it means, its kinetic energy is equal to 0.

(b) The gravitational potential energy is given by : [tex]E_p=mgh[/tex]

It can be calculated as :

[tex]E_p=2.35\times 9.8\times 21.4\\\\E_p=492.84\ J[/tex]

(c) The mechanical energy is equal to the sum of kinetic and potential energy such that,

M = 0 J + 492.84 J

M = 492.84 J

Hence, this is the required solution.

Answer: the answer would be C trust me i took the test if its not that its b

hope that helps

Explanation: i took the test

answer:

a) lower because the sound-wave fronts reach the platform at a frequency lower than the frequency at which they are produced

explanation :3

If the train is leaving the train station, then the people who are standing on the platform would hear a sound with a lower frequency since the train is moving further away. ^^

Answer:

Cytokines is the answer

Explanation:

it is another word for the chemical messanger

Answer:

a)    σ = [tex]\frac{Q_1}{ a^2 - b^2}[/tex] ,  b)  σ = [tex]\frac{Q_2}{d^2}[/tex] , c) Q_ {total} = Q₁ + Q₂,  σ_ {net} = [tex]\frac{Q_1 + Q_2}{\pi \ a^2}[/tex]

Explanation:

a) The very useful concept of charge density is defined by

          σ = Q / A

In this case we have a circular disk

The are of a circle is

         A = π r²

in this case we have a hole in the center of radius r = b, so

         A_net = π r² - π r_ {hollow} ²

         A_ {net} = π (a² - b²)

whereby the density is

          σ = [tex]\frac{Q_1}{ a^2 - b^2}[/tex]

b) The density of the other disk is

          σ = Q₂ / A₂

          σ = [tex]\frac{Q_2}{d^2}[/tex]

c) The total waxed load is requested by the larger circle

           Q_ {total} = Q₁ + Q₂

the net charge density, in the whole system is

          σ = [tex]\frac{Q_{total} }{ A_{total} }[/tex]

the area  is

          A_{total} = π a²

since the other circle is inside, we are ignoring the space between the two circles

          σ_ {net} = [tex]\frac{Q_1 + Q_2}{\pi \ a^2}[/tex]

Answer:

D

Explanation:

Answer: 0.43 m

Explanation:

Given

mass of bullet [tex]m=10\ gm\approx 0.01\ kg[/tex]

mass of block [tex]M=1.95\ kg[/tex]

The Force constant of spring is [tex]k=23.9\ N/m[/tex]

Speed of bullet is [tex]u=300\ m/s[/tex]

Conserving the energy i.e. kinetic energy of the bullet and box is converted into Elastic potential energy of spring

[tex]\Rightarrow \dfrac{1}{2}(M+m)v^2=\dfrac{1}{2}kx^2[/tex]

Conserving linear momentum

[tex]\Rightarrow mu=(M+m)v\\\\\Rightarrow v=\dfrac{mu}{M+m}[/tex]

Put the value of [tex]v[/tex] we get

[tex]\Rightarrow x=mu\sqrt{\dfrac{1}{k(M+m)}}\\\Rightarrow x=0.01\times 300\sqrt{\dfrac{1}{23.9(0.01+1.95)}}\\\Rightarrow x=3\sqrt{\dfrac{1}{46.844}}=\dfrac{3}{6.844}=0.43\ m[/tex]

Thus, spring will be compressed to a distance of [tex]0.43\ m[/tex]

Answer:

W = 1,049 10⁹ J

Explanation:

Work is defined by the relation

         W = F. d = F d cos θ

where tea is the angle between the forces and the displacement.

The total work is the sum of the work of each tug.

Tug 1

       W₁ = F d cos θ₁

the angle measured from the positive side of the x-axis is

       θ₁ = 14 + 90 = 104º

tugboat 2

             W₂ = F d cos θ₂

             θ₂ = 14

we substitute

             W = F d cos θ₁ + F d cos θ₂

             W = F d (cos θ₁ + cos θ₂)

let's calculate

             W = 1.80 10⁶  800 (cos 104 + cos 14)

             W = 1,049 10⁹ J

Answer:

I = 2387.32 A

Explanation:

Given that,

Number of turns in the loop, N = 400

The radius of the circular coil, r = 0.66 m

The magnetic field inside the MRI, B = 1.2 T

We need to find the current in the loop. The magnetic field inside the solenoid is given by :

[tex]B=\mu_o NI\\\\I=\dfrac{B}{\mu_o N}\\\\I=\dfrac{1.2}{4\pi \times 10^{-7}\times 400}\\\\I=2387.32\ A[/tex]

So, the required current is equal to 2387.32 A.

Answer:

12: If the bird flies 10m in 2s, it's speed is then 10m/2s, which we can simplify giving us 5m/s

13: Flying 5000 km in eight hours means that it's flying at (5000 / 8)km/h, or 625km/h

14: A speed graph will not go below zero, an acceleration graph will.

Answer:

. It is an extraordinarily rare, silvery-white, hard, corrosion-resistant, and chemically inert transition metal. It is a noble metal and a member of the platinum group.

Explanation:

Your question is a "non sequitur", which means "it doesn't follow".

Your "then" doesn't contradict your "If", so no mystery is implied.

Maybe you're trying to say that matter is somehow not conserved in the equation . . . 4Fe + 302 → 2Fe203 . But it is.  There are 4 Irons and 6 Oxygens on each side, so conservation is not violated here.

I looked up "rust" on Floogle, and got slapped with pages and pages of chemistry that I don't completely understand.  But what it's saying is that rusting is a very complex chemical process, AND it doesn't happen unless there's some water involved.

So the bottom line is that there's a lot more going on than simply

4Fe + 302 → 2Fe203 ,

there's water going in and out of the process at every stage, and when it's all over, you have rusty iron, and mass has been conserved.