[題目] 反射波

[colorya2001 (遨遊天空)]

[領域]波動                             (題目相關領域)

[來源]普物                             (課本習題、考古題、參考書...)

[題目]
A wave propagate on a string in the +x direction and is totally reflected
at  x=d ,where the string is tied to a post .If the incident wave function
is expressed as y(x,t)=A sin(kx-wt);then the reflected function y(x,t) must
be expressed as

Anser:A sin(kx+wt-2kd)

[瓶頸]                             (寫寫自己的想法，方便大家為你解答)

入射波y1(x,t)=A sin(kx-wt)

因為是反射波 所以設反射波為y2(x,t)=A sin(kx+wt+Φ)
而題目中條件y1(d)=0

然後就不曉得從哪下手了? 希望有高手能提示一下...

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推 linesa:在d全反射(無透射波),Asin(kd-wt)+Asin(kd+wt+Φ)=0,I+R=T
→ linesa:sin(kd-wt)=-sin(kd+wt+Φ) = sin(-kd-wt-Φ)
→ linesa:Φ=-2kd
→ colorya2001:感恩...你說的很清楚，謝謝！