Question

A harmonic wave is made to travel along a string when you move your hand up and down. The wave has a specific period T1, wavelength λ1, amplitude A1, and speed c1, and also causes a certain transverse speed v(x,t) of the particles that make up the rope. Then you repeat this up-and-down motion, this time completing the same motion twice as fast as before.Part AWhat happens to the period?A. The period is quadrupled.B. The period is halved.C. There is no change in the period.D. The period is doubled.

Answer 1

Answer:

B) True .  The period is halved

Explanation:

Let us propose the solution of the problem before reviewing the final statements.

     

The speed of a wave in a string depends on the tension and linear density of the string,

       v = √T/μ

As these two conditions do not change the speed of the wave is constant

Wave speed is related to wavelength and frequency

       v = λ f

The frequency and period are

       f = 1 / T

Let's replace

      v = λ / T

Now they tell us that the new time is twice as fast as the initial

      T = T1 / 2

For the speed to remain constant the wavelength must change

     λ= v T

     λ= v T1 / 2

    λ = λ1 / 2

Let's review the claims

A) False. It was cut in half

B) True

C) False. The period is reduced

D) False. The period is reduced