Jawabanmu

2014-04-01T21:00:01+07:00
Periode = 3 m : 12m/s = 1/4 s

periode = 1/frekuensi
frekuensi = 4Hz
1 5 1
2014-04-01T21:00:12+07:00
Lambda = 3 m
v = 12 m/s
v = f x lambda
f  = v / lambda
   = 12 / 3
   = 4 Hz
1 5 1