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>
        
             
        
        
        
It’s measured in a reference frame that is usually the earth’s surface
        
             
        
        
        
Answer:
True
Explanation:
Side affects can range from
Problems with periods to Loss of breasts