Answer:
<em>c. ABBA counterbalancing
</em>
Explanation:
The student should not use the method because it is a progressive error management technique for each subject by introducing all <em>treatment circumstances twice, first in one sequence, then in the other (AB, BA) by subject counterbalancing.</em>
If participants experience conditions more than once, they experience the conditions first in one order, then the opposite order.
Explanation:
The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault labeled "E" cuts through all three sedimentary rock layers (A, B,and C) and also cuts through the intrusion (D). So the fault must be the youngest formation that is seen and known of.
Answer: I think the answer C
Explanation:
Answer:
The beat frequency is 30 Hz
Explanation:
Given;
velocity of the two sound waves, v = 343 m/s
wavelength of the first wave, λ₁ = 5.72 m
wavelength of the second wave, λ₂ = 11.44 m
The frequency of the first wave is calculated as follows;
F₁ = v/λ₁
F₁ = 343 / 5.72
F₁ = 59.97 HZ
The frequency of the second wave is calculated as follows;
F₂ = v/λ₂
F₂ = 343 / 11.44
F₂ = 29.98 Hz
The beat frequency is calculated as;
Fb = F₁ - F₂
Fb = 59.97 HZ - 29.98 Hz
Fb = 30 Hz
is the intensity of the sound.
Answer: Option B
<u>Explanation:</u>
The range of sound intensity that people can recognize is so large (including 13 magnitude levels). The intensity of the weakest audible noise is called the hearing threshold. (intensity about
). Because it is difficult to imagine numbers in such a large range, it is advisable to use a scale from 0 to 100.
This is the goal of the decibel scale (dB). Because logarithm has the property of recording a large number and returning a small number, the dB scale is based on a logarithmic scale. The scale is defined so that the hearing threshold has intensity level of sound as 0.

Where,
I = Intensity of the sound produced
= Standard Intensity of sound of 60 decibels = 
So for 19 decibels, determine I as follows,



When log goes to other side, express in 10 to the power of that side value,

