Question

如圖為一列橫波t=0時(shí)刻波的圖象，并向右傳播，經(jīng)過(guò)1.1秒，質(zhì)點(diǎn)A第三次處于波峰，則這列波的波速為_(kāi)_____cm/s，經(jīng)過(guò)______s時(shí)間質(zhì)點(diǎn)B第一次到達(dá)波峰．

Answer 1

據(jù)題，波向右傳播，則A點(diǎn)向下振動(dòng)，則有2

3

4

T=1.1s，得到周期T=0.4s．由圖讀出波長(zhǎng)λ=2cm，則波速v=

λ

T

=5cm/s．當(dāng)圖示時(shí)刻x=1.5cm處質(zhì)點(diǎn)的振動(dòng)傳到B點(diǎn)時(shí)，質(zhì)點(diǎn)B第一次到達(dá)波峰，由經(jīng)過(guò)時(shí)間為t=

△x

v

=

6-1.5

5

s=0.9s
故答案為：5，0.9