Question

Using the data in the graphs that accompany this problem, determine a) the period of the wave.. b) the wavelength of the wave... c)the speed of the wave?

Answer 1

(a) period = 0.2 s
(b) wavelength = 0.04 m
(c) speed = 0.2 m/s

Explanation:

To find the time period, we must find how long it takes for a complete oscillation, i.e. to repeat itself. From the graph on the right, we can see that `y` is 0 at t = 0, and it is increasing then. We need to look for the next time at which the value of `y` is zero and increasing. From the graph you can see that it is 0.2 s. This is the time period.

Note that `y` does return to the value 0 at `t=0.10` s, but since it is a decreasing function there, we can not consider the interval from `t=0.00` s to `t=0.10`s to be a complete period.

Similarly, the wavelength is the distance over which `y` repeats. From the graph, we can see that it repeats over the interval `x=0` m and `x = 0.040` m. Thus, the wavelength is 0.04 m.

The speed of the wave = wavelength `times` frequency , i.e wavelength `div` time period = `0.04/0.2` m/s = 0.2 m/s