The second resonant length of an open air column is 48cm. Determine the first and third resonant lengths

Answer 1

3•λ/4 =48
λ=64 cm
1• λ /4 =16 cm
5• λ /4=80 cm

Answer 2

Sorry. For open air column
λ =L2 =48 cm
L1 =λ/2 =48/2 =24 cm,
L3 = 3• λ/2=72 cm.