Question

why is it accurate to calculate the wavelength by measuring the distance between the nodes that are the farthest apart instead of two adjacent nodes?

Answer 1

Solution :-
It is better because the end nodes are fixed/ends of the string. Any small errors in amplitutde can be transmitted through the string and can cause errors in measuring the accurate points of the nodes which are adjacent to each other. Between the two end nodes, the number of nodes through the string can be measured, the number in itself won't vary and the length of the string is already known. The wavelength thus can be calculated more accurately