9.2E: The Wave Equation (Exercises)
- Page ID
- 43348
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Q9.2.1
In Exercises 9.2.1-9.2.8 solve the initial-boundary value problem.
1. \(u_{tt}=9u_{xx},\quad 0<x<1,\quad t>0\),
\(u(0,t)=0,\quad u(1,t)=0,\quad t>0\),
\(u(x,0)=0,\quad u_t(x,0)= \left\{\begin{array}{cl} x,&0\le x\le{1\over2},\\1-x,&{1\over2}\le x\le1 \end{array}\right.,\quad0\le x\le1\)
2. \(u_{tt}=9u_{xx},\quad 0<x<1,\quad t>0\),
\(u(0,t)=0,\quad u(1,t)=0,\quad t>0\),
\(u(x,0)=x(1-x),\quad u_t(x,0)=0,\quad0\le x\le 1\)
3. \(u_{tt}=9u_{xx},\quad 0<x<2,\quad t>0\),
\(u_x(0,t)=0,\quad u(2,t)=0,\quad t>0\),
\(u(x,0)=4-x^2,\quad u_t(x,0)=0,\quad0\le x\le2\)
4. \(u_{tt}=4u_{xx},\quad 0<x<1,\quad t>0\),
\(u_x(0,t)=0,\quad u(1,t)=0,\quad t>0\),
\(u(x,0)=x^2(1-x),\quad u_t(x,0)=0,\quad0\le x\le 1\)
5. \(u_{tt}=64u_{xx},\quad 0<x<\pi,\quad t>0\),
\(u(0,t)=0,\quad u_x(\pi,t)=0,\quad t>0\),
\(u(x,0)=x(2\pi-x),\quad u_t(x,0)=0,\quad0\le x\le \pi\)
6. \(u_{tt}=64u_{xx},\quad 0<x<\pi,\quad t>0\),
\(u(0,t)=0,\quad u_x(\pi,t)=0,\quad t>0\),
\(u(x,0)=0,\quad u_t(x,0)=x(2\pi-x),\quad0\le x\le \pi\)
7. \(u_{tt}=5u_{xx},\quad 0<x<2,\quad t>0\),
\(u_x(0,t)=0,\quad u_x(2,t)=0,\quad t>0\),
\(u(x,0)=2x^2(3-x),\quad u_t(x,0)=0,\quad0\le x\le 2\)
8. \(u_{tt}=5u_{xx},\quad 0<x<2,\quad t>0\),
\(u_x(0,t)=0,\quad u_x(2,t)=0,\quad t>0\),
\(u(x,0)=0,\quad u_t(x,0)=2x^2(3-x),\quad0\le x\le 2\)