a 60-w light bulb radiates electromagnetic waves uniformly in all directions. at a distance of 1.0 m from the bulb, the light intensity is i0, the average energy density of the waves is u0, and the rms electric and magnetic field values are e0 and b0, respectively.

Remember the formula

[tex]\\ \rm\Rrightarrow A(t)=A_o(0.5)^{\frac{t}{h}}[/tex]

[tex]\\ \rm\Rrightarrow A(7.82\times 10)=A(78.2)[/tex]

[tex]\\ \rm\Rrightarrow 4.11\times 10^{76}(0.5)^{\frac{78.2}{3.91\times 10^{5}}}[/tex]

[tex]\\ \rm\Rrightarrow 4.11\times 10^{76}(0.5)^{20\times 10^{-5}}[/tex]

[tex]\\ \rm\Rrightarrow 4.11\times 10^{76}(0.5)^{0.0002}[/tex]

[tex]\\ \rm\Rrightarrow 4.11\times 10^{76}(0.998)[/tex]

[tex]\\ \rm\Rrightarrow 4.10178\times 10^{76}[/tex]

Why no options matched?

That time given in end i.e 7.82×10

The number of nuclei  of calcium-47 left after 7.82 x 10⁵s is 1.03 x 10¹⁶.

This can be found out using half life and laws of radioactive disintegration.

The Law of radioactive disintegration states  the number of  radioactive decay per unit time is proportional to the number of nuclei present in the sample initially.

So,  ΔN/Δt = λN

Where, ΔN = number of radioactive nuclei decayed

Δt = time taken for decay

N = No of nuclei present initially

λ= decay constant

Half life is the time taken for the radioactive nuclei to reach half of its initial value.

Half life is given by

 [tex]t_{1/2}[/tex] =  λ/t

Given here,  [tex]t_{1/2}[/tex] =  3/91 x 10.⁵s

N = 4.11 x 10¹⁶.

t = 7.82 x 10.⁵s

We see  here that  t = 2([tex]t_{1/2}[/tex])

Now, number of radioactive nuclei left undecayed in  one half life is N/2

So number of nuclei left undecayed in 2 half lives will be 1/2(N/2) = N/4

So number of nuclei left in the sample will be N/4 = (4.11 x 10¹⁶.)/4

So Number of nuclei left in the sample = 1.03 x 10¹⁶.

Hence 1.03 x 10¹⁶is the correct answer.

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If temperature is constant, the volume of a gas varies inversely as its pressure. The constant of proportionality for this variation is 3750.

Temperature is the degree of hotness or coldness of the object.

According to the ideal gas law, pV =nRT

where, p=pressure of gas, V =volume of gas, n=number of moles of element of gas, R=Universal Gas constant and T =temperature

When the temperature is constant,

PV =constant =k

k = 150x 25

k = 3750

Thus , the constant of proportionality is 3750.

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Answer: A Because that is local I mean it is confined to a city at least i think so

Answer:

Option 3

Explanation:

All of the mentioned options are mitigation solutions. But, the question has clearly asked for local solutions, which means it has the possibility or feasibility to take place in every neighborhood no matter where you are.

The option which correctly gives this is :

Heat capacity is the amount of heat required to raise the temperature of an object by 1oC. The specific heat of a substance is the amount of energy required to raise the temperature of 1 gram of the substance by 1oC.

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Answer

Its PO

Explanation:

I got it right on Edge.

Answer:

Radio frequency energy. (Radiation)

Explanation:

the phone is getting hot due to large amount of used electricity. Geothermal energy is getting passed from the earth through the power lines from light and turns into electricity. this is what happens in a phone as well.

This is a Uniformly Accelerated Rectilinear Motion exercise.

We obtain the following data:

Vo = 20 m/s, Vf = 35 m/s, t = 5, a = ¿?

To calculate the acceleration, subtract the final velocity minus the initial velocity, divided by the time.

a = Vf - Vo / t

Greetings

Answer:

Violet (Shortest Wave Length)

Explanation:

Violet waves have the highest frequencies. The highest frequencies have the shortest wave length.

We are asked for the x coordinate of vertex

Here vertex is present somehow at 850-870nm

The most applicible answer should be 860nm

Option C is correct

Answer:

Distance: 32 km

Displacement: 18 km

Explanation:

Distance is the total amount travelled. Displacement on the other hand is how far away an object is from its starting point.

Distance is a scalar quantity meaning it only has magnitude. Displacement is a vector quantity meaning it has magnitude and direction.

Distance is represented by "x" while displacement is represented as "Δx".

Note that "Δ" is the Greek letter "delta" which is used to represent a change in something.

Let's start by finding the distance.

Since distance is the total amount travelled, we can just add all of the values.

9km + 18km + 5km = 32 km

Then, we can find the displacement.

North and East are positive while South and West are negative.

If the athlete ran 9km East and 5km West, their displacement would be:

9km - 5km = 4km East

Now, we can set up a triangle to determine the displacement from the starting point.

18km North would be the longer leg, 4km East would be the shorter leg, and the displacement would be the hypotenuse.

Using Pythagorean's Theorem we find that:

[tex]a^2+b^2=c^2\\4^2+18^2=c^2\\16+324=c^2\\340=c^2\\c\approx18[/tex]

Note that "a" and "b" represent the legs of the triangle while "c" represents the hypotenuse of the triangle.

The displacement is approximately 18m.

The drawing of the positive charge showing the electrical fields inside  the empty volume enclosed by the shell is attached accordingly. See explanation below.

The electrostatic potential at any location outside the shell, assuming the center of the shell is Z, equals Z/4π∈₁r, where r is the distance from O.

It's also worth noting that the spherical shell's outer surface is an equipotential shell, which means that the electric field at any place inside the shell except O is zero.

Because the shell is metallic, charge Z will induce uniformly on the inner surface and +Z will induce uniformly on the outer surface, with O as the charge center.

As a result, an electric field will exist both within and outside the shell, but the total charge will remain the same.

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Explanation:

The integral of a velocity versus time function is a displacement versus time function

So we integrate,

[tex] {t}^{2} - t[/tex]

The integral of that is

[tex] \frac{1}{3} {t}^{3} - \frac{ {t}^{2} }{2} [/tex]

Plug in 12 for t,

[tex] \frac{1}{3} (12 {}^{3} ) - \frac{12 {}^{2} }{2} [/tex]

[tex]576 - 72 = 504[/tex]

So the displacement is 504 meters to the right.

vf = 12² - 12 = 132 m/s

a = vf' = 2t-1

at t =12 s,

a = 2(12)-1 = 23 m/s²

vf²=vi²+2ad (vi=initial velocity=0)

vf²=2ad

132² = 2 x 23 x d

d = 378.78 m

Answer:

Yes, it is possible.

Explanation:

Hope this helps! :)

Answer:

it's possible since scientists have already progressed to making fully transparent & invisible human organs.

Solution: Expansion

Explanation:

When we put a glass bottle in the freezer, the volume of water is supposed to expand causing high surface tension leading to the glass to crack. As the volume of water increases, there is less space for the water to fit in.

Answer:

Expansion

Explanation:

According to boyles law

According to gay lussac's law

In freezer

Hence V increases

Answer:

here

Explanation:

Copper is commonly used as an effective conductor in household appliances and in electrical equipment in general. Because of its low cost, most wires are copper-plated. You will often find electromagnet cores normally wrapped with copper wire

Answer:mirror

Explanation:

at an angle of 42° from the surface of the mirror. What angle does the reflected ray make with the normal Ans. 42° 2. A ray of light hits a mirror at 27° from the normal.

Answer:

2.76 eV

Explanation:

The Quanta of Light For example, a photon of blue light of wavelength 450 nm will always have 2.76 eV of energy.

If the same force acts upon another object whose mass is 26, the object's acceleration is  2 m/s².

It states that the force F is directly proportional to the acceleration a of the body and its mass.

The law is represented as

F =ma

Given is the mass of object m =4 kg and the acceleration a = 13 m/s², then the force will be

F = 4x13 = 52 N

The same force is acted upon the object of mass 26kg, then new acceleration will be

52N = 26 kg x a'

a' = 2 m/s²

Thus, the object's acceleration is 2 m/s²

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In gasoline-powered vehicles, most of the fuel's energy is lost in the engine, primarily as heat. Smaller amounts of energy are lost through engine friction, pumping air into and out of the engine, and combustion inefficiency.

(a) The relative velocity If those trucks move at the same time from the same place is 35 m/s.

(b) The distance between them after 2 minutes ​ is 4,200 m.

The relative velocity of the two truck is calculated as follows;

Vr = 20 m/s - (-15 m/s)

Vr = 20 m/s + 15 m/s

Vr = 35 m/s

d = Vr(t)

d = 35(2 x 60 s)

d = 4,200 m

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Answer:

Diagram B because a plate resting on a table has gravity acting on it and normal/air resistance force working against the gravity with the same amount of force. Forces that are balanced don't move.

Explanation:

I hope this helps

Diagram B represents the forces acting on the plate that is at rest on the kitchen table.

Every day, we experience the normal force.

In this instance, when we lay a plate on a kitchen table, the normal response force prevents the plate from going through the table, even if gravity is pulling the plate downward. That implies that there is a force acting to push it upward. The word "normal force" refers to the force. Normal in this context refers to being perpendicular to the ground.

Hence, in diagram B, downwards arrow represents gravitational force acting on the plate for its weight and upwards arrow represents normal force acting on the plate by the table.

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I think you might be referring to this full question:

When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward, as it typically does), we call it:

When a planet temporarily moves westward in the sky over the course of several weeks or months we call it retrograde motion.

Retrograde motion is a movement that occurs when a planet rotates at a slower speed compared to another celestial body.

This type of slow movement (retrograde motion) gives us the illusion that the planet is retrograding regarding the other celestial body.

In conclusion, when a planet temporarily moves westward in the sky we call it retrograde motion.

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Answer:

cows a consumer

Explanation:

because it can make food by its own