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
its c!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Total momentum, p = 21.24 kg-m/s
Explanation:
Given that,
Mass of first piece, 
Mass of the second piece, 
Speed of the first piece,
(along x axis)
Speed of the second piece,
(along y axis)
To find,
The total momentum of the two pieces.
Solve,
The total momentum of two pieces is equal to the sum of momentum along x axis and along y axis.






The net momentum is given by :


p = 21.24 kg-m/s
Therefore, the total momentum of the two pieces is 21.24 kg-m/s.