To develop this problem it is necessary to apply the concepts related to Wavelength, The relationship between speed, voltage and linear density as well as frequency. By definition the speed as a function of the tension and the linear density is given by

Where,
T = Tension
Linear density
Our data are given by
Tension , T = 70 N
Linear density , 
Amplitude , A = 7 cm = 0.07 m
Period , t = 0.35 s
Replacing our values,



Speed can also be expressed as

Re-arrange to find \lambda

Where,
f = Frequency,
Which is also described in function of the Period as,



Therefore replacing to find 


Therefore the wavelength of the waves created in the string is 3.49m
The question here would be what is the volume of the room. The density of air that is given has no use. We simply multiply the dimensions given of the room to determine the volume.
<span>43.0m × 18.0m × 15.0m = 11610m^3 ( 3.28 ft / 1 m)^3 = 4.09 x 10^5 ft^3</span>
Answer:
Friction is a force that opposes motion.
The index of refraction of the unknown material in which a ray of light is incident at 35° and refracted at 23° is 2.03
<h3>Snell's law</h3>
index of refraction (n) = Sine i / Sine r
n = Sine i / Sine r
Where
- i is the angle of incidence
- r is the angle of refraction
<h3>How to determine the refractive index </h3>
From the question given above, the following data were obtained:
- Index of refraction of oil (nₒ) = 1.38
- Angle of incidence (i) = 35°
- Angle of refraction (r) = 23°
- Index of refraction of unknown material (nᵣ) =?
nₒSine i = nᵣSine r
1.38 × Sine 35 = nᵣ × Sine 23
Divide both side by Sine 23
nᵣ = (1.38 × Sine 35) / Sine 23
nᵣ = 2.03
Thus, the index of refraction of the unknown material is 2.03
Learn more about Snell's law:
brainly.com/question/25758484