140 is the velocity because you need to multiply 40×2.5
Answer:
Explanation:
The definition of the intensity in terms of power is given by:
Where:
- P is the power
- A is the area
If the sound emits uniformly in all directions and that there are no reflections, we can assume the geometry of the wave sound is spherical.
Let's recall the area of a sphere is
To the first location we have:
and to the second location we have:
Now, we can divide each intensity to find the second intensity.
I hope it helps you!
Apply the Pythagorean theorem to get the resultant velocity:
V =
Given values:
Vx = 57.8m/s
Vy = 5.6m/s
Plug in and solve for V:
V = 58.1m/s
EDIT: Let's get the direction of the resultant velocity as well.
This equation will give the angle of the velocity as measured off of the ground:
θ = tan⁻¹(Vy/Vx)
Again, the given values are:
Vx = 57.8m/s
Vy = 5.6m/s
Plug in the values and solve for the angle θ:
θ = tan⁻¹(5.6/57.8)
θ = 5.5°
The resultant velocity is oriented 5.5° off the ground.