Question 30 1 pts The gure below shows the trace on an oscilloscope screen when sound waves are detected by a microphone. The time-base is set at 2 ms per division . Determine the frequency of the sound waves. Give your answer to 0 decimal places. Question 29 The gure below shows displacementtime graphs for two identical oscillators. What is the estimated phase difference between the two oscillations? time In ml 0 About 68 degrees. 0 Around 90 degrees. 0 Around 180 degrees. 0 Around 108 degrees. 0 Around 40 degrees