A student has built a $15-\mathrm{cm}$-long pinhole camera for a science fair project. She wants to photograph her $180-\mathrm{cm}$-tall friend and have the image on the film be$0.5\mathrm{cm}$ high. How far should the front of the camera be from her friend?

The Ray Structure of Light: Light passes at $v=c/n,$ via neat lines called light ray. The light ray will persist indefinitely except if it interacts with substance, in which case it will reflects, refract, disperse, or be consumed. Light rays are emitted by things. Rays are sent out in every dimensions from every spot on the item. When divergent rays are gathered either by pupil and centered just on retina, the person perceives an item (or a picture). If lens, reflectors, and apertures are bigger over $\approx 1\mathrm{mm}$, ray optics is acceptable.

Camera's height was $15\mathrm{cm}$.

$180\mathrm{cm}$would be the size of student's buddy.

That picture just on camera has a length of $5.0\mathrm{CM}$.

Pictorial representation:

Calculation:

Lets $d$represent the space between both the classmate and device's face. Its identical triangles as in diagram under show how the lengths were linked.

$\frac{5.0\mathrm{cm}}{15\mathrm{cm}}=\frac{180\mathrm{cm}}{d}$

Calculate for $d$

$d=\frac{\left(15\mathrm{cm}\right)\left(180\mathrm{cm}\right)}{5.0\mathrm{cm}}$

$=540\mathrm{cm}\text{or}5.4\mathrm{m}$