Answer:
(θ) = 60°
Explanation:
Given:
Speed of canoe Vc = 2 m/s
Speed of River Vr = 1 m/s
Computation:
Vc (Cosθ) = Vr
2 (Cosθ) = 1
(Cosθ) = 1 / 2
(Cosθ) = (Cos60)
(θ) = 60°
The answer is d.... Knife.
Hope this helped :)
A few people criticized Darwin for his theory, such as the left-leaning biologists Stephen Jay Gould and Richard Lewontin, who fear the political implications of Darwinian theory. They fear that evolutionary theory, even when bolstered by modern genetics, and molecular biology, does not make reality probable enough.
(1.a) The surface area being vibrated by the time the sound reaches the listener is 5,026.55 m².
(1.b) The intensity of the sound wave as it reaches the person listening is 0.02 W/m².
(1.c) The relative intensity of the sound as heard by the listener is 103 dB.
(2.a) The speed of sound if the air temperature is 15⁰C is 340.3 m/s.
(2.b) The frequency of the sound heard by the suspect is 614.3 Hz.
<h3>
Surface area being vibrated</h3>
The surface area being vibrated by the time the sound reaches the listener is calculated as follows;
A = 4πr²
A = 4π x (20)²
A = 5,026.55 m²
<h3>Intensity of the sound</h3>
The intensity of the sound is calculated as follows;
I = P/A
I = (100) / (5,026.55)
I = 0.02 W/m²
<h3>Relative intensity of the sound</h3>

<h3>Speed of sound at the given temperature</h3>

<h3>Frequency of the sound</h3>
The frequency of the sound heard is determined by applying Doppler effect.

where;
- -v₀ is velocity of the observer moving away from the source
- -vs is the velocity of the source moving towards the observer
- fs is the source frequency
- fo is the observed frequency
- v is speed of sound


Learn more about intensity of sound here: brainly.com/question/17062836
Answer:
Atom - the basic particle of matter
Density - calculated from measurements of mass and volume
Motion - calculated from measurements of distance and time
Energy - can change form and move matter
Matter - the scientific word for <em>stuff</em>
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