That's the "air pressure" everywhere on that area.
Answer:
The answer is B
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Explanation:
Answer:
1a) 857143 m
1b) 414 m
2a)
2b)
3) the medium of air has a wavelength of 0.334 m, the medium of water has a wavelength of 1.493 m, and the medium of 5.130 m.
Explanation:
Question 1a)
Given the velocity/speed, and frequency of the wave, the length can be calculated using these two quantites.
[ λ = v / f ] wavelength = <u>v</u>elocity of the wave / <u>f</u>requency of the wave in Hz.
Since 3 × 10^8 × ms^-1 is the velocity, and 350Hz is the frequency.
Anything to the negative power is reciprocated. i.e ms^-1 = m/s.
The wavelength is 300000000m/350Hz = 857142.8571428..... m ≈ 857143 m
Question 1b) Given that the frequency of the second wave in water is 1% of the first wave, and the speed of the second wave is 1450ms^-1
Therefore the second wave has a frequency of 1% of 3.5 = 350/100 Hz = 3.5 Hz
The wavelength is found using the same
formula: wavelength = 1450m/3.5Hz = 414.2857142857.... m ≈ 414 m
Question 2a)
Question 2b)
Question 3) Remember, the speed of sound of the medium = frequency of the medium × wavelength of the medium.
Therefore the wavelength of the medium = speed of sound of the medium / frequency of the medium. This has a similar correlation to the wavelength formula. We are given that all these mediums have a frequency of 1KHz = 1000Hz, where So the wavelength of each medium =
Question 4)
Construct a vector diagram. It will be a right-angled triangle. One vector (the hypotenuse) represents the heading of the boat, one represents the current and one represents the resultant speed of the boat, which I'll call x. Their magnitudes are 20, 3 and x. Let the required angle = theta. We have:
<span>theta = arcsin(3/20) = approx. 8.63° </span>
<span>The boat should head against the current in a direction approx. 8.63° to the line connecting the dock with the point opposite, or approx. 81.37° to the shore line. </span>
<span>x = sqrt(20^2 - 3^2) </span>
<span>= sqrt(400 - 9) </span>
<span>= sqrt 391 </span>
<span>The boat's crossing time = </span>
<span>0.5 km/(sqrt 391 km/hr) </span>
<span>= (0.5/sqrt 391) hr </span>
<span>= approx. 0.025 hr </span>
<span>= approx. 91 seconds</span>
