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Blababa [14]
3 years ago
8

A sinusoidal electromagnetic wave in a vacuum is propagating in the positive z-direction. At a certain point in the wave at a ce

rtain instant in time, the electric field points in the negative x-direction. At the same point and at the same instant, the magnetic field points in the
A. positive y-direction.
B. negative y-direction.
C. positive z-direction.
D. negative z-direction.
E. none of the above
Physics
1 answer:
Sunny_sXe [5.5K]3 years ago
4 0

Answer:

The correct answer is B negative y-direction

Explanation:

An electromagnetic wave is created by the fluctuation of the electric and magnetic fields, which are perpendicular to each other, the direction of propagation is perpendicular to these two fields.

Let's apply the above to our problem, the wave propagates in the positive direction of the z-axis so that the electric and magnetic fields must be in the xy plane

They express that the electric field is in the negative direction of the x-axis, for the direction of the other field, we can make the vectoial product E x B with the result must be in positive z the only way is that the magnetic field (B) is in the negative direction of the y axis

The correct answer is B negative y-direction

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Distance = 13.98 * 10^12 m

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work done = ΔK.E ( change in Kinetic energy )  ---- ( 1 )

<em>where :</em>

work done = p * t

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and ΔK.E = 1/2 mVf^2   given ; m = 1200 kg  and initial V = 0

<u>back to equation 1 </u>

473040000 * 10^6  = 1/2 mv^2

Vf^2 = 2(473040000 * 10^6 ) / 1200

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<u>i) Determine how fast the rocket is ( acceleration of the rocket )</u>

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<u>ii) determine distance travelled by rocket </u>

Vf^2 - Vi^2 = 2as

Vi = 0

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s ( distance ) =  Vf^2 / ( 2a )

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faltersainse [42]

Answer:

W = 5701 KW

Explanation:

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Specific volume for steam at P2 = 0.8 bar in the saturated vapour state can be gotten from saturated steam tables(find a sample of the table attached to this answer).

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