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3 years ago

7

The energy flow per unit time per unit area (S) of an electromagnetic wave has an average value of 440 mW/m2. The maximum value

of the magnetic field in the wave is closest:

1 answer:

mafiozo [28]3 years ago

7 0

To solve this problem we will proceed to convert the Intensity Units given to a normal system, that is, to standardize their value. Later we will use the value of the electric field according to the RMS electric field, to find it.

Finally the magnetic field would be given based on the previously found electric field, depending on the speed of light:

The value of the intensity is:

$I = 440mW/m^2 = 0.440W/m^2$

The maximum value of the electric field is,

$E_{max} = \sqrt{2}E_{rms}$

$E_{max} = \sqrt{2}\sqrt{Ic\mu_0}$

Where,

I = Intensity,

$\mu$ = Permeability constant

c = Speed of light

Replacing,

$E_{max} = \sqrt{2}\sqrt{(0.440)(3*10^8)(4\pi*10^{-7})}$

$E_{max} = 18.2V/m$

The maximum value of the magnetic field is,

$B_{max} = \frac{E_{max}}{c}$

$B_{max} = \frac{18.2}{3*10^8}$

$B_{max} = 6.06*10^{-8}T$

Therefore the maximum magnetic field is $7.10*10^{-8}T$

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Marysya12 [62]

Answer:

acc. = 4-(-6) /5= 10/5=2 m/s^2

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3 years ago

Time dilation: A missile moves with speed 6.5-10 m/s with respect to an observer on the ground. How long will it take the missil

tatyana61 [14]

Answer:

The time taken by missile's clock is $4.6\times 10^{6} s$

Solution:

As per the question:

Speed of the missile, $v_{m = 6.5\times 10^{3}} m/s$

Now,

If 'T' be the time of the frame at rest then the dilated time as per the question is given as:

T' = T + 1

Now, using the time dilation eqn:

$T' = \frac{T}{\sqrt{1 + (\frac{v_{m}}{c})^{2}}}$

$\frac{T'}{T} = \frac{1}{\sqrt{1 + (\frac{v_{m}}{c})^{2}}}$

$\frac{T + 1}{T} = \frac{1}{\sqrt{1 + (\frac{v_{m}}{c})^{2}}}$

$1 + \frac{1}{T} = \frac{1}{\sqrt{1 + (\frac{v_{m}}{c})^{2}}}$

$1 + \frac{1}{T} = (1 + (\frac{v_{m}}{c})^{2})^{- \frac{1}{2}}$ (1)

Using binomial theorem in the above eqn:

We know that:

$(1 + x)^{a} = 1 + ax$

Thus eqn (1) becomes:

$1 + \frac{1}{T} = 1 - \frac{- 1}{2}.\frac{v_{m}^{2}}{c^{2}}$

$T = \frac{2c^{2}}{v_{m}^{2}}$

Now, putting appropriate values in the above eqn:

$T = \frac{2(3\times 10^{8})^{2}}{(6.5\times 10^{3})^{2}}$

$T = 4.6\times 10^{6} s$

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3 years ago

How is work calculated when the force applied is not parallel to the displacement

Leno4ka [110]

Pretty sure it’s Force*Distance*Cos(theta)

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3 years ago

Read 2 more answers

A certain resistance thermometer read 14.5 ohms in pure melting ice and 18.5 ohms in steam at standard atmospheric pressure what

Vadim26 [7]

The resistance of the thermometer at room temperature is 15.04 ohms.

<h3 />

<h3>What is a resistance thermometer?</h3>

A resistance thermometer is a type of thermometer that measures temperature through a change in resistance.

To calculate the resistance of the thermometer at room temperature, we use the formula below.

Formula:

100/27 = 2/(x-14.5)..............Eqquation 1

Where:

x = Resistance of the thermometer at room temperature

Make x the subject of the equation

x = [(27×2)/100]+14.5
x = (54/100)+14.5
x = 0.54+14.5
x = 15.04 ohms.

Hence, The resistance of the thermometer at room temperature is 15.04 ohms.

Learn more about thermometers here: brainly.com/question/1531442

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2 years ago

Write an essay on basketball history and how the game has changed over time

jarptica [38.1K]

Basket ball has gone through some changes and hence got into shape as what we play or watch nowadays. Overall rules have the same fundamental principles as set in 1891 by the founder of this game.

December 21st, in 1891, the introductory basketball game was played in Springfield, Massachusetts. It was first brought into shape by a Canadian-by birth, Dr. James Naismith. The basic idea of the new game was to keep the sports loving students in shape during the winters or in between the outdoor game seasons.

'The basket ball' which had a set of thirteen basic rules set up a strong foundation to the game and still played almost in the same style with few modifications.In the very year of 1891, after mixing and changing theme of several other played games of those days, basket ball was born.

Initially, basket ball with the 13 rules was played with 2 peach baskets setup as goals, which now a days are the baskets on a high poles although modified but with same basic idea. In the very first game played in Springfield, the set of players were able to score a single point only, in the whole game.

By comparing Naismith’s basketball and basketball of today we see a characteristic of the original game which had no dribbling, instead a player had to pass the ball to a another player of his team ,from his the very spot where he caught it. The second thing which has now changed is the fouls, in the original game if any team made 3 consecutive foul play ,the oponent received a goal in reward. Although this scoring technique doesn't exist in the modern basketball. Rather nowadays, if any team makes five fouls in one quarter, the offending team is in the penalty ,and shoot free throws are awarded against them.

All other rules are quiet intact in the modern play as well. As the game today,has extended to over 2 hundered countries and enjoyed by many on television screens, with modern umpiring and technologies being used in the game, but the original idea of the founder is still endured.

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3 years ago