Answer:
The smallest film thickness is 117 nm.
Explanation:
Light interference on thin films can be constructive or destructive. Constructive interference is dependent on the film thickness and the refractive index of the medium.
For the first interference (surface nearest to viewer), the minimum thickness can be expressed as:

where n is the refractive index of the bubble film.
Therefore,


∴ 

Answer:
294.524 m^3
Explanation:
The volume of a cylinder is given by the formula ...
V = πr^2h
For a radius of 2.5 m and a length of 15 m, the volume is ...
V = π(2.5 m)^2(15 m) = 93.75π m^3 ≈ 294.524 m^3
The volume is about 294.52 cubic meters.