Physics Flashcards
Components of the electromagnetic spectrum (Smallest to largest). How does it measure light?
Gamma Ray: medicine
X-Ray: bone density scan
Ultraviolet: black lights
Visible: neon lights
Infrared: remotes
Microwave: traffic speed cameras
Radio: drones
Measured in frequency, wavelength, & energy
Define wavelength, amplitude, & frequency. Label a wave diagram.
Wavelength: The distance from crest to crest or from trough to trough.
Amplitude: The height of the wave from the rest position to the crest, or from the rest position to the trough.
Frequency: The rate of repetition of a wave.
Relationship between frequency and wavelength
The shorter the wavelength, the higher the frequency. They are proportional to each other.
Differentiate between the different methods of producing artificial light (incandescence, etc)
Incandescence: light produced by an object
Fluorescence: glass tube filled with gas
Phosphorescence: stores energy from a source of light; emits it over time
Chemiluminescence: chemical reaction produces light
Bioluminescence: plant or animal to produces light
Triboluminescence: light produced from friction
Difference between opaque, transparent, and translucent
Opaque: cannot see through (mirror)
Transparent: clear (window)
Translucent: somewhat see-through (water)
What are the primary and secondary additive colours of light? Subtractive? What colours are formed when mixing certain additive colours together?
Additive Primary: Red, Green, Blue.
Additive Secondary: Cyan, Magenta, Yellow.
Flipped for subtractive
What does the law of reflection state?
When light reflects off a smooth surface, the angle of incidence is always equal to the angle of reflection.
Difference between an umbra & penumbra? Be able to draw the formation of a shadow from an object
Umbra: all light rays are blocked
Penumbra: partial shadow
What are the characteristics of an image formed in a concave mirror when the image is in front of the focal point & behind? (LOST)
L: closer
O: upright
S: smaller
T: virtual
What are the characteristics of an image formed by a convex mirror?
-virtual
-behind
-smaller
-upright
Describe the behaviour of light when it strikes a boundary between two different substances
The light wave bends (refraction). Happens due to changes in speed of light. (Air into water)
What does the index of refraction refer to?
The ratio between speed of light in a vacuum & speed of light in a given material.
Higher refractive index to a medium with a lower refractive index?
Lower to a higher?
Higher to a lower refractive index: it will bend AWAY from the normal.
Lower to a higher refractive index: it will bend TOWARDS the normal.
Concave vs. Convex lens. Which disperses & which focuses light?
Concave (diverging): thin in the middle (disperses light)
Convex (converging): thick in the middle (focuses light)
Explain how the human eye works to detect light (pathway)
Cornea → pupil → lens → retina → optic nerve → brain
The brain interprets these signals as visual images, allowing us to see.
Human vision problems. Explain one in detail & correcting it
Far: close objects are blurry(diverging)
Near: far objects are blurry (converging)
Astigmatism: the cornea or lens has an irregular shape, causing blurry or distorted vision.
Instead of being round like a basketball, the cornea or lens is shaped more like a football, leading to light being focused in multiple points instead of just one. Causing both near and distant vision to be unclear.
