15.如圖所示,一質(zhì)點(diǎn)在A、B之間做簡(jiǎn)諧運(yùn)動(dòng),O為平衡位置,E、F點(diǎn)分別為AO和OB之間關(guān)于O點(diǎn)的對(duì)稱點(diǎn)(即EO和OF的距離相等)。質(zhì)點(diǎn)從E點(diǎn)向右運(yùn)動(dòng)經(jīng)過時(shí)間t
1第一次經(jīng)過F點(diǎn),再經(jīng)過時(shí)間t
2第四次經(jīng)過F點(diǎn),該質(zhì)點(diǎn)的振動(dòng)分別在空氣中和水中傳播形成兩列波。下列說法正確的是( ?。?/div>
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