[填空题]
Two piano strings are supposed 4o6 6u mpvr dl1tv+q7kto be 7:qs m,g::3b .-piec yqqps fjvibrating at 132 Hz, but a piano tuner hears three beats every 2.0 s when they are played togethfssp::q - my3peq7ib.g, qj:cer. (a) If one is vibrating at 132 Hz, what must be the frequency of the other ? Hz Hz
(b) By how much (in percent) must the tension be increased or decreased to bring them in tune? % increase %decrease
