Optics, Reflection, and Mechanics Review

Vocabulary practice flashcards covering geometric optics, reflection, refraction, mirrors, lenses, and mechanics principles from physics lecture problems.

Reflection of light

The bouncing of light rays off a surface or reflective boundary.

Laws of reflection of light

Two fundamental optical principles stating that: (1) the incident ray, the reflected ray, and the normal at the point of incidence all lie in the same plane; and (2) the angle of incidence equals the angle of reflection.

Real image

An image formed by the actual intersection of light rays, which can be captured and projected onto a physical screen.

Virtual image

An image formed by light rays that only appear to diverge from a point behind a mirror or lens, which cannot be formed on a screen.

Concave mirror

A curved spherical mirror whose reflective surface curves inward, capable of forming both real and virtual images depending on object distance.

Convex mirror

A curved spherical mirror whose reflective surface curves outward, which always produces an upright, diminished, and virtual image.

Mirror formula

The fundamental relationship between focal length ($f$), object distance ($u$), and image distance ($v$), given by $\frac{1}{f} = \frac{1}{u} + \frac{1}{v}$.

Magnification ($m$)

The ratio of the image height to the object height, which is also equal to the image distance divided by the object distance ($m = \frac{v}{u}$).

Plane mirror

A flat reflective surface that produces an upright, virtual, laterally inverted image located the same distance behind the mirror as the object is in front.

Periscope

An optical instrument using plane mirrors to reflect light, enabling an observer inside a submarine to view objects above the water surface.

Refraction of light

The bending or change in direction of a light ray as it passes from one transparent medium into another having a different refractive index.

Total internal reflection

The complete reflection of a ray of light within an optically denser medium when the angle of incidence at the interface exceeds the critical angle.

Critical angle ($C$)

The specific angle of incidence in an optically denser medium that produces an angle of refraction of $90^\circ$ in the rarer medium, related to refractive index by $n = \frac{1}{\sin(C)}$.

Short-sightedness (Myopia)

A vision defect where light rays from a distant object focus in front of the retina, resulting in a blurred image; corrected using a diverging (concave) lens.

Power of a lens combination

The total optical power of two lenses combined together, calculated as the algebraic sum of their individual powers ($P = P_1 + P_2$) in units of $\text{m}^{-1}$.

Focal length ($f$)

The distance from the pole of a curved mirror (or optical centre of a lens) to its principal focus, inversely related to lens power by $f = \frac{1}{P}$.

No-parallax

An optical alignment condition where there is no relative motion between an object and its image when the observer moves their eye sideways, showing they are at the exact same position in space.

Primary colours of light

Red, green, and blue light, which can be mixed in different intensities to produce white light and create most stage lighting effects.

Big drop

An amusement ride in which a passenger carriage is elevated to the top of a tall vertical tower and released into free fall before braking to rest.

Gravitational potential energy ($E_p$)

The potential energy stored in an object due to its vertical height above a reference level, calculated using the formula $E_p = mgh$.