[填空题]
An organ pipe is 112 cm long. reo8pu; 7w( reWhat arhn; o0h/s 3 ofn,ksx)v;nmg5be the fundamental and first three audible overton ;kh o)h5ns;mo vn,s3nx 0gbf/es if the pipe is
(a) closed at one end, $f_{1}$ = Hz $f_{3}$ = Hz $f_{5}$ = Hz $f_{7}$ = Hz
(b) open at both ends?$f_{1}$ = Hz $f_{2}$ = Hz $f_{3}$ = Hz $f_{4}$ = Hz