These are wave equation PDEs

(2 (+1)28 3.3.5. Given the following equation, describe the physical situation: a 22 (x + 5) (2x + 1) + +7 at2 ar ar 47 subject to BCs: du(0,t) = +2 + 2t +1 ar u(4, t) = 0 and ICs: u(t,0) = COS I + sinz - 1 Ou(x,0) = In (2+1) - 2.60759. at 3.3.6. Given the following equation, describe the physical situation: a (3.3 + 5) ata + sinet, z subject to BCs: u(0,t) = 0 u Ou(L,t) = 3 cost and ICS: u(1,0) = ln(x+1) Ou(x,0) at = 0. (2 (+1)28 3.3.5. Given the following equation, describe the physical situation: a 22 (x + 5) (2x + 1) + +7 at2 ar ar 47 subject to BCs: du(0,t) = +2 + 2t +1 ar u(4, t) = 0 and ICs: u(t,0) = COS I + sinz - 1 Ou(x,0) = In (2+1) - 2.60759. at 3.3.6. Given the following equation, describe the physical situation: a (3.3 + 5) ata + sinet, z subject to BCs: u(0,t) = 0 u Ou(L,t) = 3 cost and ICS: u(1,0) = ln(x+1) Ou(x,0) at = 0