Length of the pipe = 0.39 m
Number of harmonics = 3
Now there are 3 loops so here we can say


now here at the center of the pipe it will form Node
we need to find the distance of nearest antinode
So distance between node and its nearest antinode will be


So the distance will be 6.5 cm
We know that a=vf_vi/t equals equation "a" . Where a is the acceleration of the body , vf is the final velocity , vi is the initial velocity and t is equal to time . Since vi equals o m/s , vf equals to 60 m/s and t equals 10 s. Put in equation "a". a=60-0/10 =6m/s2
the answer for the question is D. all of the above
As the speed increases and the pressure decreases