Assuming our "closed tube" is closed at only one end, then
<span> v = fλ = f*4L/n
</span><span> where "n" is the harmonic number. So
</span><span> L = nv / 4f = n*346m/s / 4*256Hz = n*0.38 m
</span> <span>Since the only option in your list that is an integer multiple of 0.38 m is 1.35 m
</span><span> I'd say that we're hearing the fourth harmonic.
answer is
</span><span>A. 1.35 m</span><span>
</span>
Answer:
Reverberation is created when a sound produced in a sapce is reflected off surfaces, like walls, teh floor or the ceiling. ... The time it takes for this sound in the space to decrease in volume down to 60 decibels (practically silence) after the sound source is extinguished is its reverberation time.
Answer:
d = 1700 meters
Explanation:
During a rainy day, as a result of colliding clouds an observer saw lighting and a heard thunder sound. The time between seeing the lighting and hearing the sound was 5 second, t = 5 seconds
Speed of sound, v = 340 m/s (say)
Let d is the distance of the colliding cloud from the observer. The distance covered by the object. It is given by :

d = 1700 meters
So, the distance of the colliding cloud from the observer is 1700 meters. Hence, this is the required solution.
Answer:
a. It always points perpendicular to the contact surface.
Explanation:
"Normal" means perpendicular. Normal forces are always perpendicular to the contact surface.