Give you something to compare your results with. It's always nice to be able to see what changes have been made to the original, even if it's not technically the original (I know that was worded weird, I just don't know how else to explain it.) Hope this helped!
Land surfaces change, erosion happens, the ground collapses, etc.
Answer:
Y = V / f where Y equals wavelength
4 Y1 = V / f1 for a closed pipe the wavelength is 1/4 the length of the pipe
2 Y2 = V / f2 for the open pipe the wavelength is 1/2 the length of the pipe
Y1 / Y2 = 2 = f2 / f1 dividing equations
f2 = 2 f1
the new fundamental frequency is 2 * 130.8 = 261.6
(The new wavelength is 1/2 the original wavelength so the frequency must double to produce the same speed.
We know that the change in momentum is equals to the product of force and time that is impulse (
). Therefore, we need to determine the value of that the water is in air by using the second equation of motion,

Here, u is initial velocity which is zero.
.
Thus, impulse

From Newton`s second law,

Therefore, impulse

Given,
and 
Substituting these values, we get
Change in momentum = impulse
.