2.在勻質(zhì)輕繩上有兩個(gè)相距10m的波源S
1、S
2,兩波源上下振動(dòng)產(chǎn)生兩列繩波,可將其看作簡(jiǎn)諧波。兩波源的連線(xiàn)上有兩質(zhì)點(diǎn)A、B,A距S
1波源3m,B距S
2波源5m,如圖甲所示。t=0時(shí)波源S
1開(kāi)始向上振動(dòng),其振動(dòng)方程為y=10sin(10πt)cm,而波源S
2的振動(dòng)圖像如圖乙所示。t=0.2s時(shí)質(zhì)點(diǎn)A開(kāi)始振動(dòng),則下列說(shuō)法不正確的是( ?。?br />