The distance from observer A of intensity of sound 59 db is 28.64 m and the distance from observer B of intensity of sound 83 db is 11.36m
Explanation:
Let's solve this problem in parts
let's start by finding the intensity of the sound in each observer
observer A β = 59 db
β = 
where I₀ =
W / m²

=
W / m²
Similarly for Observer b 
now we use that the emitted power that is constant is the intensity over the area of the sphere where the sound is distributed
P = I A
therefore for the two observers
the area of a sphere is

we substitute the above formula, we get
Let us call the distance from the observer A be to stereo speaker = x, so the distance from the observer B to the stereo speaker = 40- x; we substitute

after solving the above equation we get x = 28.64 m
This is the distance of observer A
similarly The distance from observer B is 35 - x
= 40 - 28.64
= 11.36m
To know more about intensity of sound with the given link
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Answer:
1). Average speed = 1.5 m per second
2). Average velocity = 1.5 m per second
Explanation:
1). Since, speed is a scalar quantity
Therefore, average speed of the trip = 
From the graph attached,
Total distance covered = 10 + 10 + 20 + 0 + 20 + 30
= 90 meters
Total time taken = 60 seconds
Average speed = 
= 1.5 meter per second
2). Velocity is a vector quantity.
Therefore, average velocity = 
= 
= 
= 1.5 meter per second

Diameter of objective lens = 1.22m
Wavelength of light = 4000Å
We have to find resolving power of telescope ..
★ Resolving power of telescope is given by
RP = D/1.22λ
- D denotes diameter of lens
- λ denotes wavelength of light
RP = D/1.22λ
RP = (1.22×10⁷)/(1.22×4)
RP = 0.25 × 10⁷
RP = 2.5 × 10⁶
★ Resolving power of microscope is given by
RP = 2μsinθ/λ
We can answer this one very quickly. From the <em>Law of Conservation of Energy</em>, we know that "Energy can't be created or destroyed.".
So that only leaves us one way to complete the sentence in this question:
"One form of energy can be <em>transformed into</em> another type of energy.
" <em>(B)</em>