An air-filled pipe is found to have successive harmonics at 630 hz , 810 hz , and 990 hz . it is unknown whether harmonics below 630 hz and above 990 hz exist in the pipe. what is the length of the pipe? what type of pipe do you have?

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?