Question

A convex lens has a diameter of 30 mm and a depth of 5 mm at the center. How far from the vertex is the focus?

Answer 1

@ganeshie8 might help c:

Answer 2

i hope so @Elsa213 !

Answer 3

here the focal distance \(f\) is:
\[\frac{1}{f} = \frac{2}{R}\]
wherein \(R\) is the radius of the lens, namely:
\[R = \frac{D}{2} = \frac{{30}}{2} = ...mm\]
so the requested distance \(d\), is:
\(d=f-(5/2)=...\)