Physics Lenses

As refraction increases, light speed ____

decreases in the medium.

What is Snell’s law?

It describes the relationship between the angles of incidence and refraction when light passes through different media, defined by the equation n1 sin(θ1) = n2 sin(θ2).

approximately how much does light slow down in water

Light slows down to about 75% of its speed in a vacuum.

approximately how much does light slow down in glass

Light slows down to about 67% of its speed in a vacuum.

Why does light slow down when it enters a new medium?

When light strikes an atom it must interact with its electron cloud, thus slowing light

When a ray of light travels from a rarer medium to a denser medium, _____

it slows down and bends towards the normal.

When a ray of light travels from a denser medium to a rarer medium, __________

it speeds up and bends away from the normal.

The greater the value of n, the ____ refraction is

greater

What does it mean if a refracted ray becomes brighter

there is more reflection

What does it mean when the reflected ray becomes dimmer

there is less reflection.

The angle of refraction approaches 90 degrees until _____

total internal reflection occurs.

What is total internal reflection?

Total internal reflection is the phenomenon that occurs when a light ray strikes the boundary of a medium at an angle greater than the critical angle, preventing it from passing into the second medium and reflecting completely back into the first medium.

When the angle of incidence equals the critical angle, the angle of refraction is ____ degrees

90

When the angle of incidence is greater than the critical angle

total internal reflection occurs (light is reflected back into the same medium

When the angle of incidence is equal to the critical angle

the light refracts at an angle of 90 degrees (to the normal)

When the angle of incidence is greater than the critical angle

light is entirely reflected rather than transmitted.

Total Internal refraction

light travels along the critical angle and does not leave object

What type of lens is in the human eye

The human eye contains a convex lens

Reflection changes the _____ of a wave

direction

Refraction changes the ______ of a wave

speed

Light travels fastest in a

vacuum

Whne refraction occurs from air to water ,the angle of incidence is always

greater than the angle of refraction.

Wteh light moves from a denser medium into a less dense medium, the ray of refraction _________ from the normal

bends away

Speed of light and density of the medium are ______ related

inversely

(refraction or reflection) In a mirror when you right side moves, your reflection shows your left side moving

reflection

(refraction or reflection) A mirror in a flashlight focuses light into a beam

reflection

You look into a pool and see a coin that appears closer to the surface than it really is

refraction

Convex lenses and a _____ mirror have the same properties

concave

Concave lenses and a ______ mirror have the same properties

convex

A convex lense or concave mirror held far away will make objects appear ______

smaller than they are and inverted

Reflection

The bouncing back of light rays when they hit a reflective surface.

Refraction

The region of a wave where particles are spread apart, resulting in reduced pressure.

What is the index of refraction?

The measure of how much light slows down and bends when entering a medium from another, defined as the ratio of the speed of light in a vacuum to the speed of light in the medium.

What is internal reflection

Internal reflection occurs when light waves hit the boundary of a medium at an angle greater than the critical angle and are completely reflected back into the medium.

What are fiber optic cables used for?

Fiber optic cables are used for transmitting data as light signals over long distances with minimal loss, primarily in telecommunications and networking.

How are fiber optic cables better than copper wires?

Copper wires use electricity while fiber optic cables use light which is faster and safer.

What are applications for internal reflection

binoculars, periscopes, telescopes,

What are some uses of convex lenses

magnifying glass, cameras eyeglasses

What are some uses of concave lenses

telescopes, nearsightedness, peepholes, binoculars

What lens produces a real image

convex

What is the point where all light rays converge called?

focal point

In lenses, all real images are _______ and all virtual images are _____

inverted, upright

In mirrors, all real images are _____ and all virtual images are ______

inverted, upright

Concave lenses make light ______

diverge

Convex lenses make light

converge

the thicker the lens the more light is ____

bended

When the object is between F and O on a convex lens

image is virtual, larger, upright, and is used in a magnifying glass

When the object is between F and O on a concave lens

image is smaller, virtual, upright, used in telescopes and cameras

When the object is at F in a convex lens

no image is formed, used in telescopes

When the object is between F and C in a convex lens

Image is larger, real, inverted, and used in optical instruments

When object is at C in a convex lens

image is the same size, real, and inverted (used in optical instruments)

When the object is beyond C in a convex lens

Image is smaller, real, and inverted (used in optical instruments)

When the object is placed beyond C in a concave lens

image is smaller, virtual, and upright (used in telescopes and cameras)

What light bends the most

blue

Dispersion

bending of light at different angles in prisms and rainbows

What does the amount of refraction depend on?

The speed of light and the angle of incidence