Answer:
<u><em>A. wavelength</em></u>
Explanation:
The others are about sound and how high it is. That has nothing to do with time.
<h2>
Answer:</h2>
|B| = 47.0 units
<h2>
Explanation:</h2>
The sum of two vectors (A) and (B) gives another vector (A + B). i.e
(A + B) = (A) + (B) ----------------(i)
<em>From the question;</em>
Vector A = 28.0 units in the positive y-direction. This means that the value of the x-component is zero and the value of the y-component is +28
In unit vector notation vector A is given as;
A = 0i + 28.0j
Vector A + B = 19.0 units in the negative y-direction. This means that the value of the x-component is zero and the value of the y-component is -19.0
In unit vector notation, vector A + B is given as;
A + B = 0i - 19.0j
To get the magnitude of vector B, make B the subject of the formula in equation (i) as follows;
(B) = (A + B) - (A) ------------------ (ii)
Substitute the values of the vectors (A) and (A + B) into equation (ii) as follows;
(B) = (0i - 19.0j) - (0i + 28.0j)
(B) = - 19.0j - 28.0j
(B) = - 47.0j
The magnitude of B, |B|, is therefore;
|B| = |-47.0|
|B| = 47.0 units
The correct option is D.
Lumen is used to quantify the amount of total light energy that a source is putting out in all direction, thus, it refers to luminous output of a light source. Initial lumen refers to the luminosity of a light when it was first turned on; the luminosity is highest at this point.
