The loudspeaker is replaced by a speaker with a power rating of 50 mW. What is the change: (i) in the sound intensity? (ii) in the sound intensity level?
The human ear is more sensitive to certain frequencies of sound. How is this taken into account when measuring sound intensity levels?
2005 12. (c) The frequency of a stretched string depends on its length.
vibrating guitar string
(6)
A loudspeaker has a power rating of 25 mW. What is the sound intensity at a distance of 3 m from the loudspeaker?
(9)
(9) (4)
0.65 m Give two other factors that affect the frequency of a stretched string. (6)
The diagram shows a guitar string stretched between supports 0.65 m apart. The string is vibrating at its first harmonic. The speed of sound in the string is 500 m s–1. What is the frequency of vibration of the string?
Draw a diagram of the string when it vibrates at its second harmonic. What is the frequency of the second harmonic?
