[Adolf Hitler Chân dung má»™t trùm phát xÃÂt] [kinh tế xây dá»±ng] [TÄ©nh váºt và những bà i thÆ¡ khác] [Những bàẩn trong cuá»™c đỠi] [flute player hears four beats per second when she compares her note to a fC = 523 Hz tuning fork (thenote C). She can match the frequency of the tuning fork by pulling out the tuning joint and lengthening thepipe of the flute slightly. What was the flute player’s initial frequency ff] [Mỹ] [hán văn] [tốigiản] [phi tinh đầu số] [Tôi tài giỏi, bạn cũng thế]