As researchers cool a substance close to absolute zero, what happens?

-The work needed to cool it further falls to zero.

-The work needed to cool it further decreases, becoming easier.

-The work needed to cool it further increases.

-Work is done on the environment by the substance.

Answer:

letra A segundo o couculo a divisão e completa

Answer:

The drift speed of the electrons in the wire is 2.12x10⁻⁴ m/s.

Explanation:

We can find the drift speed by using the following equation:

[tex] v = \frac{I}{nqA} [/tex]

Where:

I: is the current = 4.50 A

n: is the number of electrons

q: is the modulus of the electron's charge = 1.6x10⁻¹⁹ C

A: is the cross-sectional area = 2.20x10⁻⁶ m²

We need to find the number of electrons:

[tex] n = \frac{6.022\cdot 10^{23} atoms}{1 mol}*\frac{1 mol}{26.982 g}*\frac{2.70 g}{1 cm^{3}}*\frac{(100 cm)^{3}}{1 m^{3}} = 6.03 \cdot 10^{28} atom/m^{3} [/tex]                  

Now, we can find the drift speed:

[tex]v = \frac{I}{nqA} = \frac{4.50 A}{6.03 \cdot 10^{28} atom/m^{3}*1.6 \cdot 10^{-19} C*2.20 \cdot 10^{-6} m^{2}} = 2.12 \cdot 10^{-4} m/s[/tex]              

Therefore, the drift speed of the electrons in the wire is 2.12x10⁻⁴ m/s.

I hope it helps you!      

Answer: I think it C and B but I am really confident in C

Explanation:

Answer:

it’s 2.5 m/s

Explanation:

i’m too lazy but trust

This question can be solved by using the law of conservation of momentum.

The final speed of the lighter 2 kg train is " 2.5 ".

When two moving objects collide with each other, the law of conservation of momentum can be applied to them as follows:

[tex]m_1u_1+m_2u_2=m_1v_1+m_2v_2[/tex]

where,

m₁ = mass of heavier train = 3 kg

m₂ = mass of lighter train = 2 kg

u₁ = initial speed of heavier train = 2.8

u₂ = initial speed of lighter train = 1.6

v₁ = final speed of heavier train = 2.2

v₂ = final speed of lighter train = ?

Therefore,

(3 kg)(2.8) + (2 kg)(1.6) = (3 kg)(2.2) + (2 kg)(v₂)

[tex]v_2 = \frac{5 kg}{2 kg}[/tex]

v₂ = 2.5

Learn more about the law of conservation of momentum here:

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The attached picture illustrates the law of conservation of momentum.

Answer:

Explanation:

For original spring , compression in spring due to a load of 1355 kg is

x = 12 - 8.55 = 3.45 cm = .0345 m

spring constant = W / x

= 1355 x 9.8 / .0345

= 384898.55 N /m

Spring constant of new spring

k = 384898.55 - 5655 = 379243.55 N /m

New compression for new spring

= W / k

= 1355 x 9.8 / 379243.55

= .035 m

= 3.50 cm

Difference of compression = 3.50 - 3.45

= .05 cm .

In later case , car will be more lowered by .05 cm .

Answer:

D. Weight

Explanation:

Hope that helps:)

A. Synthesis, decomposition, single-replacement, combustion

List of reaction types are redox reactions:

"Redox reactions are oxidation-reduction chemical reactions in which the reactants undergo a change in their oxidation states." The term 'redox' is a short form of reduction-oxidation. All the redox reactions can be broken down into two different processes – a reduction process and an oxidation process.

Know more about redox reaction here

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#SPJ2

Answer:

C.  changing nuclear energy to radiant energy

Explanation:

Nuclear energy takes atoms in their potential state, split them (fission) or fuse them (fusion)  creating chain reactions of radiant energy.  Most nuclear electrical power plants use fission, radiant energy heats water making steam to spin turbines.

Or think of the atom bomb.  Definitely potential energy until the fuse starts detonation and chain reactions.  The radiant kinetic energy and shock waves were horrendous.

Answer:

The answer would be C, changing nuclear energy to radiant energy

Explanation:

Welcome have a good day.

Answer:

The electric potential at the center of the meter stick is 54 KV.

Explanation:

Electric potential (V) is given as:

i.e V = [tex]\frac{kq}{r}[/tex]

Where: k is the Coulomb constant, q is the charge and r is the distance.

Given: q = 3.0 μC = 3.0 x [tex]10^{-6}[/tex] C, r = 0.5 m

So that,

V = [tex]\frac{9*10^{9}*3.0*10^{-6} }{0.5}[/tex]

   = [tex]\frac{2.7*10^{4} }{0.5}[/tex]

V = 54000

  = 54 000 volts

The electric potential at the center of the meter stick is 54 KV.

Answer:

D

Explanation:

The net force is the combination of all forces acting on an object.

Answer:

the required revolution per hour is 28.6849

Explanation:

Given the data in the question;

we know that the expression for the linear acceleration in terms of angular velocity is;

[tex]a_{c}[/tex] = rω²

ω² = [tex]a_{c}[/tex] / r

ω = √( [tex]a_{c}[/tex] / r )

where r is the radius of the cylinder

ω is the angular velocity

given that; the centripetal acceleration equal to the acceleration of gravity a [tex]a_{c}[/tex]  = g = 9.8 m/s²

so, given that, diameter = 4.86 miles = 4.86 × 1609 = 7819.74 m

Radius r = Diameter / 2 = 7819.74 m / 2 = 3909.87 m

so we substitute

ω = √( 9.8 m/s² / 3909.87 m )

ω = √0.002506477 s²  

ω = 0.0500647 ≈ 0.05 rad/s  

we know that; 1 rad/s = 9.5493 revolution per minute

ω = 0.05 × 9.5493 RPM

ω = 0.478082 RPM  

1 rpm = 60 rph  

so  

ω = 0.478082 × 60

ω = 28.6849  revolutions per hour  

Therefore, the required revolution per hour is 28.6849

The required revolution per hour is 28.6849

The expression for the linear acceleration with respect to the angular velocity is

= rω²

So,

ω² =  / r

ω = √(  / r )

Here r represent the radius of the cylinder

ω represent the angular velocity

Now

diameter = 4.86 miles = 4.86 × 1609 = 7819.74 m

And,

Radius r = Diameter / 2 = 7819.74 m / 2 = 3909.87 m

So,

ω = √( 9.8 m/s² / 3909.87 m )

ω = √0.002506477 s²  

ω = 0.0500647 ≈ 0.05 rad/s  

Now

1 rad/s = 9.5493 revolution per minute

So,

ω = 0.05 × 9.5493 RPM

ω = 0.478082 RPM  

Now

1 rpm = 60 rph  

so  

ω = 0.478082 × 60

ω = 28.6849  revolutions per hour  

Learn more about the cylinder here: https://brainly.com/question/17262276

Answer:

7.5 m/s

Explanation:

Unfortunately, I don't have an explanation but I guessed the correct answer.

Answer:

D

Explanation:

If you need an explanation feel free to ask.

Answer:

swimming, cycling, jump rope, brisk walking, gardening, jogging

Answer:

true

Explanation:

Answer:

true

Explanation:

please give brainlest need 1

Answer:

The minimum coefficient of friction required is 0.35.  

Explanation:

The minimum coefficient of friction required to keep the crate from sliding can be found as follows:

[tex] -F_{f} + F = 0 [/tex]      

[tex] -F_{f} + ma = 0 [/tex]      

[tex] \mu mg = ma [/tex]

[tex] \mu = \frac{a}{g} [/tex]

Where:

μ: is the coefficient of friction

m: is the mass of the crate

g: is the gravity

a: is the acceleration of the truck

The acceleration of the truck can be found by using the following equation:

[tex] v_{f}^{2} = v_{0}^{2} + 2ad [/tex]

[tex] a = \frac{v_{f}^{2} - v_{0}^{2}}{2d} [/tex]

Where:  

d: is the distance traveled = 46.1 m

[tex] v_{f}[/tex]: is the final speed of the truck = 0 (it stops)      

[tex]v_{0}[/tex]: is the initial speed of the truck = 17.9 m/s

[tex] a = \frac{-(17.9 m/s)^{2}}{2*46.1 m} = -3.48 m/s^{2} [/tex]        

If we take the reference system on the crate, the force will be positive since the crate will feel the movement in the positive direction.  

[tex] \mu = \frac{a}{g} [/tex]  

[tex] \mu = \frac{3.48 m/s^{2}}{9.81 m/s^{2}} [/tex]

[tex] \mu = 0.35 [/tex]

Therefore, the minimum coefficient of friction required is 0.35.  

I hope it helps you!

Answer:

yo imma so I dunno find out yourself

Explanation:

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Answer:

P = 84.1 MPa

Explanation:

       [tex]P = \rho * g * h (1)[/tex]

       where ρ = density of salt water (in Kg/m³),

       g = acceleration due to  gravity  (in m/s²)

       h = height of the column of water.

      [tex]P = \rho * g * h = 1023.6kg/m3*9.8m/s2*8380m = 84.1 MPa (2)[/tex]

Answer:

A. 171.24 Ibs

Explanation:

To find the amount of salt in the tank,

Let Q = Amount of salt in the mixture

And let 100 + (3-2)t = 100 + t be the volume of mixture at anytime t.

Rate of gain - Rate of loss = dQ / dt

Concentration of salt = Q / (100+t)

For the linear differential equation,

dQ / dt = 3(2) - 2 [Q/ (100 + t)]

dQ /dt + Q [2 / (100 + t)] = 6

The general solution of the linear differential equation is:

Q (i.f) = ∫ A(t) (i.f) dt + C

Therefore,

i.f = e ^ ∫ P(t) dt

And P(t) = 2 / (100 + t)

i.f = e ^ ∫ 2 / (100 + t)

  = e ^ 2㏑ (100 + t)

     = e ^ ㏑ (100 + t) ^2 = (100 + t) ^2

Q(100 + t) ^ 2 = ∫6 (100 + t) ^2 dt + C

 Q(100 + t) ^2 = 2(100 + t) ^ 3 + C

  When t = 0, Q = 50

Therefore,

50( 100) ^2 = 2(100) ^3 + C

 C = -1.5 * 10 ^6

therefore, when t = 30,

Q (100 + 30) ^2 = 2(100 + 30) ^3 - 1.5 * 10 ^6

 Q (400) ^2 = 2(130) ^3 - 1.5 * 10 ^6

    Q = 171.24 Ibs

The amount of salt in the tank at the end of 30 minutes is 171.24 lbs.

The given parameters:

The linear differential equation of the salt solution is calculated as follows;

[tex]\frac{dx}{dt} = Gain - loss[/tex]

where;

The salt concentration at time t, is calculated as follows;

[tex]\frac{dx}{dt} = 2(3) - 2(\frac{X}{100 + t} )\\\\\frac{dx}{dt} = 6 - 2(\frac{X}{100 + t} )\\\\\frac{dx}{dt} +2(\frac{X}{100 + t} ) =6[/tex]

Apply the general solution of linear differential equation as follows;

[tex]X(f) = \int\limits {At} \, dt \ + C\\\\f = e^{\int\limits {At} \, dt}\\\\ f = e^{\int\limits {\frac{2}{100 + t} } \, dt}\\\\f = e^{2 ln(100 + t)}\\\\f = (100 + t)^2[/tex]

[tex]X(100 + t)^2 = \int\limits {6(100 + t)^2} \, dt \ + \ C\\\\ X(100 + t)^2 = 2(100 + t)^3 + C[/tex]

When t = 0 and X = 50

[tex]50(100 + 0)^2 = 2(100+ 0)^3 + C\\\\C = -1.5 \times 10^6[/tex]

When t = 30 min, the concentration is calculated as;

[tex]X (100 + 30)^2 = 2(100 + 30)^3- 1.5 \times 10^6\\\\X(130)^2 = 2(130)^3 - 1.5\times 10^6\\\\X(130)^2 = 2894000\\\\X = \frac{2894000}{130^2} \\\\X = 171.24 \ lbs[/tex]

Learn more about solution of Linear differential equation here: https://brainly.com/question/5508539

Answer: B. A light in a swimming pool comes on after dark to prevent

accidents in the water.

Answer:

The potential between the plates will decrease.

Explanation:

An insulator is usually placed between the parallel plates and is also called a dielectric because it makes the amount of charge a capacitor can accommodate to increase at a particular potential difference.

Furthermore, the dielectric effect will make the electric field of the charged capacitor which is not connected to a source of supply to decrease.

Now, when the battery is removed, the charge Q remains constant and Capacity C will increase.

Formula for the potential difference is here;

V = Q/C

Since the numerator Q is constant and the denominator C increases, it means the potential difference V will decrease

Answer:

the answer is B: 35,136

Explanation:

force = mass × acceleration

force = 9760 × 3.6

35,136 = 9760 × 3.6

Answer:the speed of the clay immediately before impact =72.58m/s

Explanation:

Given that  

mass of the stick clay, M₁= 14.0 g = 0.014 kg

mass of the block ,M₂= 90 g = 0.09 kg

Therefore the total mass= (M₁+M₂) = 104g = 0.104 kg

Also, distance, s = 7.50 m

coefficient of friction μ= 0.650

Acceleration due to gravity ,g = 9.8 m/s²

Using the Work- Energy theorem,

change in kinetic energy =  work done

final kinetic energy(K₂) - initial  kinetic energy(K₁) =   force, F x coefficient of friction, μ x distance,s

The final kinetic energy is zero  because after the impact,  the block with the clay comes to a stop after 7.50m

kinetic energy =Work done

0.5 x m x v²=coefficient of friction,  μ x force(F)  x  distance,s(Since force = m g )

0.5 x m x v²= μ x m x g x s

0.5 x 0.104 x v² = 0.650 x 0.104x 9.8 x 7.5

v²= 0.650 x 0.104x 9.8 x 7.5 / 0.5 x 0.104

v²==95.55

V = 9.77 m/s

Using the  conservation of momentum formulae where

M₁ V₁ + M₂ V₂ = (M₁ + M₂ ) V

Since V₂  which is the velocity of block  is zero as the  block is initially at rest, We now have that

M₁ V₁ = (M₁ + M₂ ) V

0.014 kg x V₁ = 0.104 x 9.77

V₁=0.104 x 9.77 / 0.014

V=72.58m/s

Answer:

Their kinetic energies would be the same

Explanation:

This is because, since the force, F acting on them moves the same distance, d, the work done by the force is W = Fd.

Now, from work-kinetic energy principles,

W = ΔK where ΔK = change in kinetic energy of the carts.

Since the work-done is the same for both carts, their change in kinetic energies would also be the same.

Since they start from rest, ΔK = K' - K =  K' - 0 = K'

So, the kinetic energies of the carts would be the same

Answer:

Explanation:

The volume of the tank = 50 kton

50 kton = 5 × 10⁷ kg

Since 18 grams of water will contain: 10 electrons × 6.023 × 10²³

Then;

5× 10⁷ kg will contain [tex]( \dfrac{5 \times 10^7 \times 10^3}{18}) \times 10 \times 6.023 \times 10^{23}[/tex]

= 1.67 × 10³⁴ electrons

(b)

Suppose:

[tex]f_{neutrino} = \dfrac{2f_o}{26.2 MeV} = 6.7\times 10^{10} \ s^{-1} cm^{-2}[/tex]

Then;

10⁻⁶ of [tex]f_{neutrino} = 6.7 \times 10^{10} \times 10^{-6} \ s^{-1} cm^{-2}[/tex]

[tex]=6.7 \times 10^{4}\ s^{-1} cm^{-2}[/tex]

Thus, the number of high energy neutrinos which will interact with water is:

= [tex]6.7 \times 10^4 \times \sigma[/tex]

= [tex]6.7 \times 10^4 \times 10^{-43}[/tex]

= [tex]6.7 \times 10^{-39} s^{-1}[/tex]

For  1.67 × 10³⁴ electrons, the detection rate is:

[tex]6.7 \times 10^{-39} \times 1.67 \times 10^{34}[/tex]

[tex]= 11.19 \times 10^{-5} \ s^{-1}[/tex]

= 9.668 per day

Answer:

a

Explanation:

Answer:

C= 50km/hr west

Explanation:

150/3= 50

Because it asks for velocity, make sure to include the direction as well.

Answer:

a) True

b) True

c) false

d) True

e) True

Explanation:

a) True

In forward bias, the resistance of the p–n junction reduces and hence the electric charges can flow easily.

b) True

In reverse bias condition, the electric current is due to the minority charge carriers (negative).

c) False

direction of diffusion current is in the direction of movement of positive charge i,e towards n side

d) True

Because the breakdown of charge carriers occur due to which the current increases rapidly

e) True