PHYSICS · Multi-part · Fermi University Physics · Optics & Photonics · Geometrical optics and imaging · Geometrical optics and imaging
Optics and Photonics, Ch Image formation by mirrors and lenses
Problem
A ray diagram for a thin lens in air, drawn for a hiker's map-reading glass, shows these two facts and nothing else. The ray leaving the top of the map detail parallel to the axis emerges from the lens and crosses the axis at a point 6.0 cm to the right of the lens. The emergent rays, extended backwards as broken lines, form an upright image exactly twice the height of the map detail. Rays are paraxial and the lens is thin. Sign convention CV1: so>0 for a real object on the left, si>0 for a real image on the right, heights positive above the axis.
((a)) State the focal length of the lens, with its sign, and explain in one sentence which drawn feature gives it.
((b)) Find the object distance and the image distance.