Answer:
330.24 Hz
Explanation:
Given:
Frequency, f = 320 Hz
L1 = 25.8 cm
L2 = 78.4 cm
L3 = 131.1 cm
Let the wavelength be λ
Then, L1 which is the length of the column of air is λ/4.
λ/4 = 25.8 cm
λ = 25.8 × 4 = 103.2 cm = 1.032 m
Then, speed of sound in air is:
v = λ f
⇒ v = 1.032 × 320 Hz
⇒ v = 330.24 m/s
Answer:
The bottom of the sea is 25 m below sea level.
Explanation:
Given data
Mass = 6.1 × 

We know that Buoyant force on the tank is equal to gravity force of the tank.



1020 ×
= 6.1 × 
= 598039.21 
We know that
= W × L × H
598039.21 = 300 × 80 × H
H = 25 m
Therefore the bottom of the sea is 25 m below sea level.
C) the moon does not have a strong magnetic field
Answer:
The answer is "telescopes".
Explanation:
Throughout ancient times, astronomical observatories have indeed been available, and so many historical locations were reserved for astronomical observations. All contemporary astronomers lacked within those older telescopes were lenses until 1610. A telescope is indeed an instrument used to view far-off objects. Telescopes often are being used to look at planets and stars.