Answer the following questions based on the
following figure.
1.
What is the peak amplitude of this wave?
+ 5 or -5
1.
What is the instantaneous amplitude of this wave at the following times: 0, 0.75,
1.5, 2.25, and 3 seconds?
0, 0, 0, 0, and 0
1.
Based on the above values, calculate the RMS amplitude of this wave.
0
2.
Would the RMS amplitude be different if instantaneous amplitudes at times 0.125,
0.625, 1.125, 1.625, and 2.125 s were used?
Yes, because the instantaneous amplitude at each of these points is + 5.
Based on these values, the RMS amplitude is 5.

In your opinion, is it better to pick fewer or more points to calculate RMS
amplitudes?
The most accurate RMS value is obtained if a large number of
instantaneous amplitudes is picked. More important, these points must be
close to each other. For example, if 100 points between times 0 and 0.5 s
are picked, this gives a more accurate RMS value than if only 10 points
are picked.
Calculate the frequency and time period of the
following wave.
Frequency: 10 cycles/1 s = 10 Hz
Time period: 1/10 = 0.1 s
Answer the following questions.
1.
Wave A has a frequency of 100 Hz. Wave B completes one cycle in
10 s. What can be said about the two waves?
a. They have the same frequency
b. They have the same amplitude
c. Wave A has a higher frequency than wave B
d. Wave B has a higher frequency than wave A
2.
Wave C completes 300 cycles in 30 seconds. Calculate the time
period and frequency of this wave.
If the wave completes 300 cycles in 30 seconds, it will take
0.1 s (30/300) to complete one cycle. Hence, the time
period is 0.1 s. The frequency of this wave is 10 Hz. This
can be calculated either using number of cycles per second
(300/30) or by taking the reciprocal of the time period
(1/0.1)
Plot the waveform (time and displacement on horizontal and vertical
axes, respectively) of wave C showing at least three complete cycles.
Assume that the peak displacement of wave C is 10 mm.
Frequency: 10 Hz, Time period: 0.1 s, Peak displacement: 10 mm
Can be drawn in any of the following ways.