1. The problem statement, all variables and given/known data The length of a stretched string is 1m. Its mass per length is 2x10-3kg/m. The string resonates at its 4th harmonic at 400Hz. (a) Calculate the velocity of the string wave. (b) Calculate the string tension. 2. Relevant equations fn = nv / 2L v² = F / μ 3. The attempt at a solution I honestly don't know how to go about this. (a) v = √F / μ will give me the answer I suppose. μ is the linear density, how do I calculate that? Also for F, which is tension, relates to question (b) and I'm totally unsure how to calculate tension. I don't know what nv stands for either, it's pretty hard to Google nv. 2L is 2 * length of the string, which is 2m. I need some serious help please!