Jawabanmu

2014-04-06T08:54:51+07:00
2 puncak gelombang=1 gelombang. ...v=35 m/s.....panjang gelombang (lamda)=140cm=1, 4m....v=lamda*f.....35=1, 4*f....f=25Hz....T=1/f=1/25=0, 04 s