Force = mass times acceleration

A chain saw produces a spherical sound wave having a frequency of 214Hz in air at 358C (308.2K or 958F). At a distance of 600mm

Helen [10]

Given Information:

Frequency = 214 Hz

Temperature = 358° C = 308.2 K

Sound Pressure = p = 100 dB = 2 pascal

Distance = 600 mm = 0.60 m

Required Information:

(a) Acoustic Power Level = ?

(b) Acoustic Particle Velocity = ?

and Velocity level at a distance of 600 mm = ?

Answer:

Acoustic Power Level = Lw = 106.44 dB

Acoustic Particle Velocity = v = 0.0106 m/s

Velocity level = 60.25 dB

Explanation:

(a) Acoustic Power Level

Acoustic Power = W = 4πr² I

Acoustic Intensity = I = p ²/Z₀

Where Z₀ is the characteristic impedance of air Z₀ = 409.8 rayl

I = p ²/Z₀ = (2)²/409.8 = 0.00976 W/m²

W = 4πr² I = 4*π(0.60)²*0.00976 = 0.0441 W

Acoustic Power Level = Lw = 10log(W/Wref)

Where Wref is Reference Acoustic Power Wref = 1x10⁻¹² W

Lw = 10log(W/Wref) = 10log(0.0441/1x10⁻¹²) = 106.44 dB

Lw = 106.44 dB

(b) Acoustic Particle Velocity

Acoustic Particle velocity = v = p ²/Zs

Where Zs is specific acoustic impedance

Zs = Z₀kr/(1 + k²r²)⁰°⁵

Where k = 2πf/c and c = 346.1 m/s is the speed of sound in air

k = 2π*214/346.1 = 3.885 per m

Zs = 409.8*3.885*0.60/(1 + (3.885)²(0.60)²)⁰°⁵

Zs = 376.6 rayl

v = p ²/Zs = 2²/376.6 = 0.0106 m/s

v = 0.0106 m/s

Velocity level = 10log(v/vref) where vref = 10x10⁻⁹ m/s

Velocity level = 10log(0.0106/10x10⁻⁹) = 60.25 dB

Velocity level = 60.25 dB

8 0

4 years ago

Why is there a minimum mass for an object to become a star? smaller objects cannot be detected from earth. smaller objects canno

Julli [10]

Answer:

1. smaller objects cannot generate enough pressure to start hydrogen fusion.

2. 10,000,000

Explanation:

1. Stars are born in stellar nurseries known as nebula. A nebula is cloud of dust and gases. The disk of dust and gases when spins and gathers more and more mass, the temperature and pressure rises. If sufficient mass is gathered and right temperature and pressure is achieved fusion reaction starts and a star is born. Thus, smaller objects cannot generate enough pressure to start hydrogen fusion.

2. the core of a star must reach a temperature of 10,000,000 degrees Celsius for hydrogen fusion to begin.

Hydrogen fusion reaction in sun is:

$_1^1\textrm{H}+_1^1\textrm{H}\rightarrow 1^2\textrm{H}+_{+1}^0\textrm{e}+\text{energy}\\\\_1^2\textrm{H}+_1^1\textrm{H}\rightarrow 2^3\textrm{He}+\text{energy}\\\\_2^3\textrm{He}+_1^1\textrm{H}\rightarrow _2^4\textrm{He}+_{+1}^0\textrm{e}+\text{energy}$

Overall reaction for the above series of reactions is given by:

$4_1^1\textrm{H}\rightarrow _2^4\textrm{He}+2_{+1}^0\textrm{e}+\text{energy}$

3 0

3 years ago

Read 2 more answers

Read each scenario and then answer the question. Scenario A: A 6-kg bucket is raised a distance of 6 m. Scenario B: A 9-kg bucke

MAXImum [283]

Answer:

Scenario C: A 12-kg bucket is raised a distance of 4 m.

Explanation:

I just took the quiz and that's the correct answer

6 0

3 years ago

Read 2 more answers

A seed can be round when parents are crossed, scientists refer to the first generation of offspring as

lora16 [44]

Hey there!

A seed can be round when parents are crossed, scientists refer to the first generation of offspring as F1. This is the first generation of seeds from very different parental types.

Thank you!

4 0

4 years ago

How was the earth formed

liubo4ka [24]

Answer: Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust

5 0

3 years ago