what is the second longest wavelength for a standing wave on a wire with one fixed end and one open end that is 3.0 m long?

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

i wanna say it’s between b and d, leaning more towards b.