tolong bantu jawab ya.. soal no. 2, 4,5

no. 5
diket : w = 4
k : 6
dit: fλ
w = 2 phi.f
f = w/2 phi
f = 4/2 phi
f = 2 phi

k = 2 phi/lambda
lambda = 2 phi/k
lambda = 2 phi/ 6
lambda = 1/3 phi
lambda = 0.33 phip