Question

I need help understanding these problems, they’re a bit difficult

Two pulses on a string, both traveling at 10m/s, are approaching each other. A snapshot at t-0s is shown below a) Draw d snapshot graph D (in mm) of the string at t-ls. b) Draw da snapshot graph of the string at t-1.2s. c) Which time (a or b) had a point 2 on the string with the greatest displacement? Att - 0s 10 m/s 10 m/s x (in m) 10 15 20 25 D (in mm) At t-1.2s x (in m) 10 15 20 25

Answer 1

PFA for the answers
a) snap shot graph of the string at t = 15 b) Snapshot graph of the string at t = 1.25 (c) Comparing t = 15(snapshot) with t = 1.25(snapshot) rightarrow Hence t = 15 has a high displacement \r\n From the above x_1 = 7 x_2 = 11 therefore Path length difference = delta x = x_2 - x_1 delta x = 4m Phase difference rightdoublearrow delta phi = phi_2 - phi_1 we know that phi_2 = 5.5 pi, phi_1 = 3.5 phi rightdoublearrow delta phi = 2 pi Interference - Destructive delta x, delta phi are same since the nodes are same Thus for(c) Interference constructive (D) Destructive from the above x_1 = 5m x_2 = 9m path difference delta x = 4m phase diff rightarrow delta phi = phi_2 - phi_1 rightdoublearrow 4.5pi phi_1 = 2.5m delta phi = 2 pi Interference-Destructive