Posted by James on .
Which one of the following will form a standing wave: (1) two waves of the same amplitude and speed moving in the same direction (2) two waves of the same amplitude and speed moving in the opposite directions, (3) any two traveling waves can form standing wave if they have same amplitude (4) any two traveling waves can form standing wave if they have same energy
From what I've read in my textbook, I believe the answer is (2). Is this correct. Thank you in advance.

Physics 
drwls,
(2) Same amplitude, opposite directions.