Ch 6: Problem Set (in progress)

Question 1

find the other item.

Answer 1

• 2.76 Hz = 0.36 sec
• 11.8 sec = 0.085 Hz
• 0.436 kHz = 2.29 x 10^-3 sec
• 5/8 sec = 8/5 Hz

Question 2

what are the frequency and velocity of a wave where wavelength = 0.787 m and period = 2.65 sec?

Answer 2

frequency = 0.3773 Hz

and

velocity = 0.297 m/s a.f.s.

Question 3

what are the wavelength and period of a wave moving at 376 cm/s a.f.s. @ 808 cHz?

Answer 3

frequency = 0.124 sec

wavelength = 46.5 cm

(note: photo should read T = 1/8.08 = 0.124

Question 4

if a sound is 4.8 x 10^-9 W/m² at 15.2 m from a source, what is the intensity at 36.4 m from the source?

Answer 4

8.352 x 10^-10 W/m²

Question 5

if a sound is 2.06 x 10^-11 W/m² at 66.3 m from the source, what is the intensity at 19.7 m?

Answer 5

2.34 x 10^-11 W/m²

Question 6

if a sound is 5.11 x 10^-7 W/m² at 31.3 m from the source, at what distance is it 2.48 x 10^-6 W/m² ?

Answer 6

14.2 m

Question 7

Answer 7

(5 cycles)

wavelength = 0.09 m

T = 0.0027 sec

F = 370 Hz

v = 33.3 m/s a.f.s.

Question 8

Answer 8

(5.5 cycles)

wavelength = 0.8 cm

T = 0.02 sec

F = 50 Hz

v = 40 cm/s a.f.s.

Question 9

Answer 9

(4 cycles)

wavelength = 2.27 km

T = 6.83 sec

F = 0.15 Hz

v = 0.332 km/s a.f.s.