To solve this problem it will be necessary to apply the interference principle. Under this principle interference is understood as a phenomenon in which two or more waves overlap to form a resulting wave of greater, lesser or equal amplitude. In this case, if both are at the same point, the result of the total displacement will be the sum of the individual displacements, therefore
[tex]x = \sum h_i[/tex]
[tex]x = 60cm + 80cm[/tex]
[tex]x =140cm[/tex]
Therefore the resulting displacement above equilibrium is 140cm
