Answer:à
Explanation:waves carry energy in the direction in which they move
Answer:
All of the above
Explanation:
all of the reactions use up energy to achieve the end product.
Answer:
<em> The intensity would be 0.01432 W/</em>
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Explanation:
The sound intensity is the power that is transmitted by a sound wave per unit area.
Given that
Power output P of the 75-piece orchestra = 72.0 W
The listener's distance r = 20.0 m
The intensity of sound waves (I) can be obtained with the expression below;
I = P/A .............. 1
where P is the power
A is the area, in this case, at the distance r the sound is radiated through a sphere.
A = area of a sphere = 4π
putting it into equation 1, the intensity would be;
I = P/ 4π
Substituting our values we have;
I = 72.0 W / 4 π

I = 0.01432 W/
Therefore the intensity would be 0.01432 W/
Supposing the runner is condensed to a point and moves upward at 2.2 m/s.
It takes a time = 2.2/g = 2.2/9.8 = 0.22 seconds to increase to max height.
Now looking at this condition in opposite - that is the runner is at max height and drops back to earth in 0.22 s (symmetry of this kind of motion).
From what height does any object take 0.22 s to fall to earth (supposing there is no air friction)?
d = 1/2gt²= (0.5)(9.8)(0.22)²= 0.24 m
Im pretty sure the answer is c; velocity is usually measure by a vector :)