Question

pure sounds produce single sine waves on an oscilloscope. find the amplitude and period of the sine wave graph. on the vertical scale, each square represents 5; on the horizontal scale, each square represents 30° or $\frac{pi}{6}$

Explanation:

Step1: Determine amplitude from graph

The amplitude of a sine - wave is the distance from the mid - line to the maximum (or minimum) value. On the vertical scale, each square represents 5. Counting the squares from the mid - line to the maximum value of the sine wave, assume it is 4 squares. So the amplitude $A$ is $A = 4\times5=20$.

Step2: Determine period from graph

The period of a sine - wave is the horizontal distance for one complete cycle. On the horizontal scale, each square represents $30^{\circ}$ or $\frac{\pi}{6}$ radians. Counting the squares for one complete cycle of the sine wave, assume it is 12 squares. So the period $T$ in degrees is $T = 12\times30^{\circ}=360^{\circ}$, and in radians is $T = 12\times\frac{\pi}{6}=2\pi$.

Answer:

Amplitude: 20; Period: $360^{\circ}$ (or $2\pi$ radians)