Answer
(a) The bubble is thick enough for constructive interference but not for destructive interference at visible wavelengths.
(b) $108nm$
Work Step by Step
(a) We know that the thickness of the soap bubble is given as
$t=\frac{(m+\frac{1}{2})\lambda}{2n}$
We plug in the known values to obtain:
$t=\frac{(0+\frac{1}{2})(575\times 10^{-9}m)}{2(1.33)}$
$t=108nm$
We also know that the condition for destructive interference is given as
$2nt=m\lambda$
$\implies t=\frac{m\lambda}{2n}$
$t=\frac{(1)(575\times 10^{-9}m)}{2(1.33)}=216.2nm$
Thus, the bubble is thick enough for constructive interference but not for destructive interference at visible wavelengths.
(b) We know from part(a) that the possible thickness of the soap film lies in between $108nm$ wavelengths.