1.Density of the material building the raft must be lower than the water.
<span>2. Material must not react with water. </span>
<span>3.Material must have high strength. </span>
<span>4.Raft must be wide in-order to avoid drawing in the river.</span>
Answer:
Person B
Explanation:
Person B will hear the frequency that is lower than the B- flat.
Answer:
The velocity is 
Explanation:
From the question we are told that
The mass of the bullet is 
The initial speed of the bullet is 
The mass of the target is 
The initial velocity of target is 
The final velocity of the bullet is is 
Generally according to the law of momentum conservation we have that
=> 
=>
Answer:
constructive interference in which waves strengthen each other
Explanation:
Some definitions:
- Costructive interference occurs when two (or more) waves meet each other in phase, so with same displacement at the same point. In such situation, the two waves strengthen each other, and the amplitude of the resultant wave is the sum of the amplitudes of the individual waves
- Destructive interference occurs when two waves meet each other in anti-phase, so with opposite displacement at the same point. In such situation, the two waves cancel each other out, and the amplitude of the resultant wave is the difference of the amplitudes of the individual waves (which means zero if the two waves are identical)
For light waves interfering with each other, 'white' means costructive interference, while 'black' means destructive interference (because black is absence of colors, so this means that the waves cancel each other out). In this problem, we see that point X, Y and X are white, therefore they are point of constructive interference, where the waves strengthen each other.
Answer:
242.85 Hz
Explanation:
For maximum intensity of sound, the path difference,ΔL = (n + 1/2)λ/2 where n = 0,1,2...
Since Abby is standing perpendicular to one speaker, the path length for the sound from the other speaker to him is L₁ = √(2.00² + 5.50²) = √(4.00 + 30.25) = √34.25 = 5.85 m.
The path difference to him is thus ΔL = 5.85 m - 5.50 m = 0.35 m.
Since ΔL = (n + 1/2)λ/2 and for lowest frequency n = 0,
ΔL = (n + 1/2)λ/2 = (0 + 1/2)λ/2 = λ/4
ΔL = λ = v/f and f = v/4ΔL where f = frequency of wave and v = velocity of sound wave = 340 m/s.
f = 340/(4 × 0.35) = 242.85 Hz
