Answer: Its answer C: A wheelbarrow is more difficult to move as More objects are placed inside.
Explanation: The greater the mass of the object the more force is needed to make it move.
Hope this helps!! :)
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
B. is it i just got done this in class like two weeks ago hope it helps