Tolong bantu jawab no 4 dan 5 beserta caranya

4.
lamda = S/n = 3m/2 = 1,5m
f = n/t = 2/0,2s = 10Hz
v = lamda × f = 1,5m × 10Hz = 15m/s

5.
lamda = S/n = 45m/1,5 = 30m

maaf kalau salah

Dik:
S: 45 m
n: 1,5 gel
Lamda(panjang gelombang: s/n
=45/1,5
=30
Cuma memperbaiki yaa