14 mm [W] + 27 mm [W] =

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

answer(20) psi;