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3 years ago

The quantity of charge q (in coulombs) that has passed through a surface of area 2.00 cm2 varies with time

Physics

1 answer:

Makovka662 [10]3 years ago

7 0

Explanation:

We have,

Surface area, $A=2\ cm^2=0.0002\ m^2$

The current varies wrt time t as :

$q(t) = 4t^3 + 5t + 6$

(a) At t = 2 seconds, electrical charge is given by :

$q(t) = 4t^3 + 5t + 6\\\\q(2) = 4(2)^3 + 5(2) + 6\\\\q=48\ C$

(b) Current is given by :

$I=\dfrac{dq}{dt}\\\\I=\dfrac{d(4t^3 + 5t + 6)}{dt}\\\\I=12t^2+5$

Instantaneous current at t = 1 s is,

$I=12(1)^2+5=17\ A$

Current density is given by electric current per unit area.

$J=\dfrac{I}{A}\\\\J=\dfrac{(12t^2+5)}{0.0002}\\\\J=5000(12t^2+5)\ A/m^2$

Therefore, it is the required explanation.

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When monochromatic light shines perpendicularly on a soap film (n = 1.33) with air on each side, the second smallest nonzero fil

Anika [276]

Let us start from considering monochromatic light as an incidence on the film of a thickness t whose material has an index of refraction n determined by their respective properties.

From this point of view part of the light will be reflated and the other will be transmitted to the thin film. That additional distance traveled by the ray that was reflected from the bottom will be twice the thickness of the thin film at the point where the light strikes. Therefore, this relation of phase differences and additional distance can be expressed mathematically as

$2t + \frac{1}{2} \lambda_{film} = (m+\frac{1}{2})\lambda_{film}$

We are given the second smallest nonzero thickness at which destructive interference occurs.

This corresponds to, m = 2, therefore

$2t = 2\lambda_{film}$

$t = \lambda_{film}$

The index of refraction of soap is given, then

$\lambda_{film} = \frac{\lambda_{vacuum}}{n}$

Combining the results of all steps we get

$t = \frac{\lambda_{vacuum}}{n}$

Rearranging, we find

$\lambda_{vacuum} = tn$

$\lambda_{vacuum} = (278)(1.33)$

$\lambda_{vacuum} = 369.74nm$

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3 years ago

Elements with positive valences usually ______ electrons

Leno4ka [110]

The answer is donate, therefore elements with positive valences usually donate electrons

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3 years ago

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IRISSAK [1]

You are correct earth science is studied to predict planetery changes

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3 years ago

Read 2 more answers

A thin soap bubble of index of refraction 1.33 is viewed with light of wavelength 550.0nm and appears very bright. Predict a pos

faust18 [17]

Answer:

The possible thickness of the soap bubble = $1.034\times 10^{-7}\ m.$

Explanation:

<u>Given:</u>

Refractive index of the soap bubble, $\mu=1.33.$
Wavelength of the light taken, $\lambda = 550.0\ nm = 550.0\times 10^{-9}\ m.$

Let the thickness of the soap bubble be $t$ .

It is given that the soap bubble appears very bright, it means, there is a constructive interference takes place.

For the constructive interference of light through a thin film ( soap bubble), the condition of constructive interference is given as:

$2\mu t=\left ( m+\dfrac 12 \right )\lambda.$

where $m$ is the order of constructive interference.

Since the soap bubble is appearing very bright, the order should be 0, as $0^{th}$ order interference has maximum intensity.

Thus,

$2\mu t=\left (0+\dfrac 12\right )\lambda\\t=\dfrac{\lambda}{4\mu}\\\ \ = \dfrac{550\times 10^{-9}}{4\times 1.33}\\\ \ = 1.034\times 10^{-7}\ m.$

It is the possible thickness of the soap bubble.

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3 years ago

In an insulated vessel, a quantity of hot water at temperature T1 is mixed with a different quantity of cold water at temperatur

erastovalidia [21]

Answer:Water Only

Explanation:

Given

vessel is insulated therefore no heat can be added or removed i.e. heat exchange is zero

If hot water at $T_1$ is mixed with cold water at $T_2$ then at equilibrium vessel contains only water and final temperature of water will be between $T_1$ and $T_2$

Heat released by hot water is equal to heat gain by cold water .

4 0

3 years ago