Natasha holds the two ends of a string in her hands and then moves her hands up and down so that a wave travels from one end of the string to the other end. In which case will she have a standing wave along the string?

AThe resultant wave rises and falls in amplitude over time and has a frequency equal to that of the waves.

BThe resultant wave has a fixed amplitude and a frequency twice that of the waves.

CThe resultant wave has a fixed amplitude and a frequency equal to that of the waves.

DThe resultant wave rises and falls in amplitude over time and has a frequency twice that of the waves.

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qwertyuiop13 qwertyuiop13 · Answer 1 · 2017-03-06T23:37:44-05:00

The awnser to this question is B

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aristocles aristocles · Answer 2 · 2019-04-18T19:55:58-04:00

Answer:

C. The resultant wave has a fixed amplitude and a frequency equal to that of the waves.

Explanation:

When a wave superimpose with its own reflected wave then the resultant two waves will form a standing wave

so here let say the two waves are

\(y_1 = Asin(\omega t - kx)\)

\(y_2 = A sin(\omega t + kx)\)

now by superposition principle of above two waves

\(y = y_1 + y_2\)

\(y = Asin(\omega_1t - kx) + A sin(\omega_2t + kx)\)

\(y = 2Acos(kx)sin(\omega t)\)

so above is the resultant standing wave equation in which frequency will remain same and amplitude is fixed or constant