# 1.The mass of a string is , and it is stretched so that the tension in it is 180 N. A transverse wave traveling on this string has a frequency of 260 Hz and a wavelength of 0.60 m. What is the length of the string?

2.A rocket engine emits of sound energy every second. The sound is emitted uniformly in all directions. What is the sound intensity level, measured relative to the threshold of hearing, at a distance of 85 m away from the engine?

Thanks

can some1 plz help me!!!!

## Of course! I'll be happy to help you with your questions.

1. To find the length of the string, we can use the relationship between wave speed, frequency, and wavelength. The wave speed (v) can be calculated by dividing the tension in the string (T) by the linear mass density (μ) of the string: v = √(T/μ).

First, let's calculate the linear mass density of the string (μ). The linear mass density (μ) is the mass of the string (m) divided by its length (L): μ = m/L.

Given: Tension (T) = 180 N, Frequency (f) = 260 Hz, Wavelength (λ) = 0.60 m

We need to find the length of the string (L).

1. Calculate the linear mass density (μ): μ = m/L.

2. Substitute the values into the equation for wave speed: v = √(T/μ).

3. Calculate the wave speed (v) using v = fλ.

4. Substitute the values of wave speed (v), frequency (f), and wavelength (λ) into equation v = fλ to solve for v.

5. Substitute the values of tension (T) and wave speed (v) into the equation v = √(T/μ) to solve for μ.

6. Finally, calculate the length of the string (L) using μ = m/L.

2. To find the sound intensity level, we need to calculate the sound intensity first. The sound intensity (I) is the power (P) of the sound wave divided by the area (A) over which the sound wave is spread: I = P/A.

Given: Sound energy emitted per second (E) = 1 J/s, Distance from the engine (r) = 85 m

We need to find the sound intensity level, measured relative to the threshold of hearing, at a distance of 85 m away from the engine.

1. Calculate the sound intensity (I) using I = E/A.

2. Calculate the area (A) using the formula for the surface area of a sphere: A = 4πr².

3. Substitute the values of sound energy emitted per second (E) and distance from the engine (r) into the formula for sound intensity (I) to solve for I.

4. Finally, calculate the sound intensity level (L), measured relative to the threshold of hearing, using the formula: L = 10 log(I/I₀), where I₀ is the reference intensity for the threshold of hearing.

I hope this helps you! Let me know if you have any further questions.