1.What is the intensity of 140 dB sound? 2. What is the intensity level in deibe

Question

1.What is the intensity of 140 dB sound?

2. What is the intensity level in deibels of a sound that has an intensity of 2.1E-4 W/m2?

3. A person on a pier counts the splashes of a wave as the crests hit the pier's support post. If 95 splashes are heard in 0.6 minutes and a particular crest travels a distance of 7 meters in 3 seconds, what is the length of single wave?

4.Young's modulus for steel is 2.07 x 1011 and it's density is 7,790 kg/m3. Compute the speed of sound in a steel rod.

5.A transverse wave has a wavelength of 30 cm and vibrates with a frequency of 406 Hz. What is the speed of this wave?

Explanation / Answer

1)

The intensity of sound in dB is

140 dB = 10 log ( I / 10^ -12 )

I = 1.20*10^ -6 W / m^2

2)

I in ( dB) = 10 log ( 2.1*10^-4 W/m^2 / 10^ -12 )

= 665 dB

4)

youngs modulus

Y = F L / A (delta L )

= m a L / A (delta L )

= ( m / AL ) ( v )

speed v = Y /(density )

= ( 2.07*10^ 11 ) /( 7790)

= 2.65*10^ 7 m/s

5)

speed of the wave

v = ( lamda ) f

= ( 30*10^ -2 m ) ( 406 Hz )

= 121.8 m/s

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.