A wave traveling on a Slinky® that is stretched to 4 m takes 4.97 s to travel the length of the Slinky and back again.(a) What is the speed (in m/s) of the wave? 1.61 m/s b) Using the same Slinky® stretched to the same length, a standing wave is created which consists of seven antinodes and eight nodes. At what frequency (in Hz) must the Slinky be oscillating? Hz =

Respuesta :

Given:

The length of the slinky is: L = 4 m.

The time taken by the wave to travel the length and back again is: t = 4.97 s

To find:

a) The speed of the wave

b) The frequency of the wave

Explanation:

a)

As the wave on the slinky travels along the length and back again, it covers a distance that is double the distance of the slinky.

Thus, the total distance "d" traveled by the wave will be 2L.

The speed "v" of the wave is given as:

[tex]\begin{gathered} v=\frac{d}{t} \\ \\ v=\frac{2L}{t} \end{gathered}[/tex]

Substituting the values in the above equation, we get:

[tex]\begin{gathered} v=\frac{2\times4\text{ m}}{4.97\text{ s}} \\ \\ v=\frac{8\text{ m}}{4.97\text{ s}} \\ \\ v=1.61\text{ m/s} \end{gathered}[/tex]

Thus, the speed of the wave is 1.61 m/s

b)

The standing wave created consists of seven antinodes and eight nodes. Thus, the length of the slinky is 7/2 times the wavelength of the wave.

[tex]L=\frac{7}{2}\lambda[/tex]

Rearranging the above equation, we get:

[tex]\lambda=\frac{2}{7}L[/tex]

Substituting the values in the above equation, we get:

[tex]\lambda=\frac{2}{7}\times4\text{ m}=\frac{8\text{ m}}{7}=1.143\text{ m}[/tex]

The speed "v" of the wave is related to its wavelength "λ" and a frequency "f" as:

[tex]v=f\lambda[/tex]

Rearranging the above equation, we get:

[tex]f=\frac{v}{\lambda}[/tex]

Substituting the values in the above equation, we get:

[tex]\begin{gathered} f=\frac{1.61\text{ m/s}}{1.143\text{ m}} \\ \\ f=1.41\text{ Hz} \end{gathered}[/tex]

Thus, the frequency of the wave on the slinky is 1.41 Hz.

Final answer:

a) The speed of the wave is 1.61 m/s.

b) The frequency of the oscillation of the slinky is 1.41 Hz.