Answer:
For the given conditions the fundamental frequency is 3728.26 Hertz
Explanation:
We know that for a pipe open at one end and closed at other end the fundamental frequency is given by

where
f is the fundamental frequency
is the speed of sound in air in the surrounding conditions.
L = Length of the pipe
Applying values we get and using speed of sound as 343m/s we get

It’s 49% of its original gig hope this helps!
Work = force * distance
and newton*meters = Joule
In this case, work = 250N*50m = 12500 J
So the answer is D) 12,500 J