Two long strings A and B, each having linear mass density 1 2 × 10 − 2 kg m − 1 , are stretched by different tensions 4 8 N and 7 5 N respectively and are kept parallel to each other with their left ends at x = 0. Wave pulses are produced on the strings at the left ends at t = 0 on string A and at t = 20 ms on string B. When and where will the pulse on B overtake that on A?

Question

Philoid · Accepted Answer

At t = 100 ms at x = 20 m

Suppose v and v’ are wave speeds in string A and B respectively.

At the time, wave starts travelling in string B, A wave has travelled,

So, Relative Speed between A and B is 5m m/s.

So, time taken to overtake is,