1. You watch a distant carpenter driving his nails in the side of a house at a regular rate of 1 stroke per second. You hear the sound of blows exactly synchronized with blows you see. You then hear one more blow after you see him stop hammering. How far away is he? Justify your respond.
2. Assume you sound a 1056-Hz tuning fork at same time you strike a note on piano and hear 2 beats/second. You tighten piano string extremely slightly and now hear 3beats/second. What is the final frequency of piano string? Be certain to briefly elucidate your answer.
3. The threshold of hearing is 10-12 watts/m2 or 0 dB. How many times more intense than threshold of hearing is 70dB and what is the real intensity (in watts/m2) at the 70 dB level? Show physics.
4. Assume you blow top of a bottle and hear a resonance sound (standing wave). The length of bottle is about 25cm. If speed of sound in air is about 340 cm/sec., what is frequency of the sound you hear? Draw a diagram to demonstrate the standing wave in bottle. Wavelength can be determined through knowing the length and number of harmonics. Here, we take first harmonic that would be four times the length, so
5. If you “bow” a string on the violin you hear a note with a frequency of 1020 Hz. If the length of the string is about 40cm, what is the “wave” on string? Draw a diagram to demonstrate the standing wave on the string.