Flashcards in Chapter 5 Review Deck (50):
What is the particle model of light?
The particle model was create by Sir Isaac Newton, and imagines light to be a stream of tiny particles traveling in lines until they reach the eye.
What is the ray model of light?
The ray model of light represents light as a straight line that shows the direction of the light wave's travels.
What is optics?
Optics is how light moves.
What does your vision depend upon?
Your vision depends upon the amount of light entering your eye.
How does matter affect light?
The type of matter in an object determines the amount of light it absorbs, reflects, and transmits.
What does transparent mean?
Transparent is when light can travel through a matter freely. Window glass is transparent when you can see clearly through it.
What does translucent mean?
Translucent is when most light rays get through but they are scattered in many directions. Objects cannot be seen clearly, like through frosted glass.
What does opaque mean?
Opaque means light cannot pass through the matter, like a wall. The matter absorbs and reflects light, but no light passes through.
How is a shadow formed?
A shadow is formed because the light rays are blocked by the object
How can the size of a shadow be determined?
The size of a shadow is a relationship between the distance of the object from its light source.
If you have two shadows from the same shape object, what can you tell about the distance between the object and the light source?
The larger shadow is cast by the object that is closer to the light source.
Why is paper not a mirror?
Paper is not a mirror because microscopically it is a rough surface and a mirror must be totally smooth to reflect all light.
what is an incident ray?
An incident ray is the initial ray of light coming in towards the mirror.
What is a reflected ray?
A reflected ray is the ray that bounces off the mirror.
How are the angles of incident and reflected rays similar?
The angle of incidence and reflection are equal.
What is the law of reflection?
The law of reflection proves that the angle of incidence and reflection will always be the same.
If a light ray hits a mirror at a 60 degree angle, what will the angle of reflection be?
The angle of reflection will be 60 degrees.
What is refraction?
Refraction is when a ray or wave is bent.
How can light be refracted?
Light can be refracted when it enters a new medium, such as water.
Why is the light ray refracted in water?
Light will be refracted because it slows down in the new medium.
What is 'normal'
normal' is a right angled line meeting the surface it is an imaginary line drawn perpendicular to a reflecting or refracting surface at the point where an incident ray strikes the surface.
What happens when light refracts through air?
When some air is hotter than other spots we see a mirage.
What creates the illusion of water in a mirage?
The water is created by the hotter air near the ground bends the light as it gets to the ground and it reflects the sky image.
Why does a fish in the water appear to be closer to the surface than it really is?
Your brain assume that the light has not been refracted, so the image is misinterpreted.
What is a plane mirror?
A plane mirror is a smooth mirror, usually found in a home.
How do you know your reflection is in a plane mirror?
In a plane mirror, your reflection will be equal distance into the mirror as you are away from the mirror, the orientation will be the same, and your size will be the same
What is the only difference in the reflection in a plane mirror?
Your image is reversed.
What is a concave mirror?
A concave mirror curves inwards.
What is a focal point?
The focal point is the place where all the reflected rays meet.
What is converging?
When all the rays meet at one point they are said to be converging --- joining
how does a concave mirror change the image?
From a distance the image is small and upside down, as the item gets closer it stays upside down but gets larger. As the item gets past the focal point, the image becomes larger than in real life and goes upright.
what are some uses for a concave mirror?
Concave mirrors are used in flashlight, car headlights and lighthouses because the focal point concentrates the light. Shaving and make up mirrors enlarge the image to give greater detail
What is a convex mirror?
A convex mirror curves outwards.
How are the light rays reflected in a convex mirror?
The light rays are reflected as if the focal point was behind the mirror.
How do object appear in a convex mirror?
Convex mirrors make the object appear smaller, and more objects can be seen in the mirror.
Where are convex mirrors used?
Convex mirrors are used in security mirrors in stores and libraries. They widen the view in vehicle side mirrors.d
What happens to light when it enters a new denser material?
When light enters a denser material it bends or refracts toward the 'normal'
What happens when light travels into less dense material?
When light travels to less denser material it bends or refracts away from 'normal'
What is a lens?
A lens is a transparent material that refracts the light in such a away as to converge or diverge parallel light rays.
What does the shape of the lens change?
The shape of the lens changes the image that is formed.
How are lenses like mirrors?
Lenses can be convex or concave
What is a concave lens?
A concave lens is thinner in the middle than on the edge.
How do rays of light behave when they go through a concave lens?
Through a concave lens, light rays do not meet at a focal point. The image is upright and smaller than the actual object.
When are concave lenses used?
Concave lenses are used in some eyeglasses and some telescopes, usually combined with other lenses.
What is a convex lens?
A convex lens is thicker in the middle than at the edge.
How do light rays behave through a convex lens?
Through a convex lens, light rays converge at a focal point, the image will be flipped upside down. (inverted)
What happens to light that passes through the direct center of a convex lens?
The light passing through the direct center of a convex lens does not refract.
What is focal length?
Focal length is the distance from the centre of the lens or mirror to the focal point.
What are the three mathematical rules for a convex lens?
1. If the object is +2focal lengths away from the lens, the object is smaller and inverted. 2. If the object is between 1-2 focal lengths away from the lens, the object is larger and still inverted, 3. If the object is less than one focal length away, the object seems to be on the other side of the lens and is upright