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2 years ago

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Elephants can communicate over distances as far as 6 km by using very low-frequency sound waves. What is the wavelength of a 10

Hz sound wave emitted by an elephant? Assume air temperature is 20∘C.

1 answer:

harkovskaia [24]2 years ago

3 0

The characteristics of the sound waves allow to find the result for the wavelength is:

λ = 34.29 m

The sound wave is a longitudinal traveling wave, where the speed of the wave depends on the air temperature.

v = $v_o \sqrt{1 + \frac{T}{273} }$

where v₀ is the speed of sound for T = 0ºc v₀ = 331 m / s.

indicate that the temperature is T = 20ºC, let's find the speed of the traveling wave.

v = 331 $\sqrt{1 + \frac{20}{273} }$

v = 342.9 m / s

The speed of sound is related to wavelength and frequency.

v = λ f

λ = $\frac{v}{f}$

Let's calculate

$\lambda = \frac{342.29}{10}$

λ = 34.29 m

In conclusion using the characteristics of sound waves we can find the result for the wavelength is:

λ = 34.29 m

Learn more here: brainly.com/question/21995826

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Answer:

$v_f=9,07~m/s$

Explanation:

<u>Constant Acceleration Motion</u>

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Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

$v_f=v_o+at$

The car initially travels at vo=7.35 m/s and accelerates at a rate of $a=0.824~m/s^2$ during t=2.09 s.

The final velocity is:

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2 years ago

A maser is a laser-type device that produces electromagnetic waves with frequencies in the microwave and radio-wave bands of the

rusak2 [61]

Answers:

a) $T=7.04(10)^{-10} s$

b) $5.11(10)^{12} cycles$

c) $2.06(10)^{26} cycles$

d) 46000 s

Explanation:

<h2>a) Time for one cycle of the radio wave</h2>

We know the maser radiowave has a frequency $f$ of $1,420,405,751.786 cycles/s$

In addition we know there is an inverse relation between frequency and time $T$ :

$f=\frac{1}{T}$ (1)

Isolating $T$ : $T=\frac{1}{f}$ (2)

$T=\frac{1}{1,420,405,751.786 cycles/s}$ (3)

$T=7.04(10)^{-10} s$ (4) This is the time for 1 cycle

<h2>b) Cycles that occur in 1 h</h2>

If $1h=3600s$ and we already know the amount of cycles per second $1,420,405,751.786 cycles/s$ , then:

$1,420,405,751.786 \frac{cycles}{s}(3600s)=5.11(10)^{12} cycles$ This is the number of cycles in an hour

<h2>c) How many cycles would have occurred during the age of the earth, which is estimated to be $4.6(10)^{9} years$ ?</h2>

Firstly, we have to convert this from years to seconds:

$4.6(10)^{9} years \frac{365 days}{1 year} \frac{24 h}{1 day} \frac{3600 s}{1 h}=1.45(10)^{17} s$

Now we have to multiply this value for the frequency of the maser radiowave:

$1,420,405,751.786 cycles/s (1.45(10)^{17} s)=2.06(10)^{26} cycles$ This is the number of cycles in the age of the Earth

<h2>d) By how many seconds would a hydrogen maser clock be off after a time interval equal to the age of the earth?</h2>

If we have 1 second out for every 100,000 years, then:

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3 years ago

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uysha [10]

Answer:

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The formula for potential is

V = kq/r............................ Equation 1

Where V = electric potential, k = proportionality constant, q = charge, r = distance.

making q the subject of the equation,

q = Vr/k............................ Equation 2

Given: V = 490 V, r = 10 m,

Constant: k = 9×10⁹ Nm²/C²

Substitute into equation 2

q = 490(10)/(9×10⁹)

q = 5.4×10⁻⁷ C

q = +5.4×10⁻⁷ C

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since the mass of the child and that of the swing is negligible, the masses wont be involved in the calculation

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Answer:

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