Oscillations and Waves
Beginner
Wave function
Source: High school physics (Chinese)
Problem Sets:
Waves
Problem
A simple harmonic wave travels along a rope. A point on the rope takes $0.17$ s to move from the position of maximum displacement back to its equilibrium position.
- Find the period and the frequency.
- If the wavelength is $1.4$ m, find the wave speed.
$T = 0.68$ s; $f \approx 1.5$ Hz; $v \approx 2.1$ m/s.
Moving from the maximum displacement to the equilibrium position is one quarter of a full cycle, so $\dfrac{T}{4} = 0.17$ s, giving $T = 0.68$ s. The frequency is $f = \dfrac{1}{T} = \dfrac{1}{0.68} \approx 1.5$ Hz. With $\lambda = 1.4$ m, the wave speed is $v = \dfrac{\lambda}{T} = \dfrac{1.4}{0.68} \approx 2.1$ m/s.