Question 19.WE.1: Figure 19.10 shows displacement–time graphs for two identica...
Figure 19.10 shows displacement–time graphs for two identical oscillators. Calculate the phase difference between the two oscillations. Give your answer in degrees and in radians

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Step 1 Measure the time interval t between two corresponding points on the graphs.
t = 17 ms
Step 2 Determine the period T for one complete oscillation.
T = 60 ms
Hint: Remember that a complete oscillation is when the object goes from one side to the other and back again.
Step 3 Now you can calculate the phase difference as a fraction of an oscillation.
phase difference = fraction of an oscillation
Therefore:
phase difference = \frac{t}{T} = \frac{17}{60} = 0.283 oscillation
Step 4 Convert to degrees and radians. There are 360° and 2π rad in one oscillation.
phase difference = 0.283 × 360° = 102° \approx 100°
phase difference = 0.283 × 2π rad
= 1.78 rad \approx 1.8 rad