The figure shows the `y – x` graph at an instant for a small amplitude transverse wave travelling on a stretched string. Three elements (1, 2 and 3) on the string have equal original lengths `(= Deltax)`. At the given instant-
(i) which element (among 1, 2 and 3) has largest kinetic energy?
(ii) which element has largest energy (i.e., sum of its kinetic and elastic potential energy)
(iii) Prove that energy per unit length `(DeltaE)/(Deltax)` of the string is constant everywhere equal to `T((del y)/(del x))^(2)` where `T` is tension the string.

Answer

(a) 2
(b) 2