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Draw a ray.

How long do you have to wait to see in the dark?

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Never will be able to see,

nothing emitted

Describe the conditions

necessary to see light

Has to reflect off an object and into your eyes

Draw the light rays emitted from one point on a candle.

How does a pinhole work? Draw the

object and image.

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What causes the formation of

shadows?

When light shines on an object, some of the rays may be stopped while others pass on in a straight-line path

What is the difference between a shadow and a semi-

shadow?

Shadow- clearly defined

Semi-shadow- fuzzy, light can pass

Draw the shadow. Is it a shadow or a

semi-shadow?

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Shadow Draw the shadow. Is it a shadow or a

semi-shadow?

Semi-shadow What is an eclipse? Provide an example

Solar eclipse: moon passes between earth

and sun

Lunar eclipse: earth passes between sun

and moon

What is the law of reflection?

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Angle of incidence = angle of reflection

What type of image do plane

mirrors produce?

Virtual How big a mirror

do you need to see your entire body?

Include a ray diagram.

A mirror half your height (diagram on

board) What is the

normal? Why is it so important?

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Normal = perpendicular to the surface; rays reflect

about the normal

A 50 cm dog stands 3 m from a plane mirror

and looks at its image. Draw a ray

diagram for the dog. Describe the image.

Virtual, same size, same distance.

Diagram on board

What type of image can a concave

mirror form?

Real or Virtual depending on

location in relation to focal point

Where is the focal point located for a

convex mirror? What type of image is always formed?

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Behind the mirror, virtual image

What type of mirror is this? Why is there a

warning?

Convex, diverging light increases vision but decreases size of car

Draw a ray diagram. Describe the image.

See board. Real, reduced, inverted

Draw a ray diagram. Describe the image.

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See board.Virtual, magnified, upright

What is refraction?

The bending of light

Describe how light bends as it changes

mediums

Bends towards the normal if entering a more dense medium, bends away from the normal if entering less

dense medium

Draw the refracted rays

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Diagram on board How do rainbows form? Draw a ray

diagram!

Different wavelengths of

colored light refract differently, becomes

trapped

Why does the road look hazy on a hot summer day? Draw a ray diagram.

Hot air different density than cold air, refracts more. Diagram on board

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Why is it dangerous to stare into the

sun?

A lot of light moving through a small

opening and being concentrated on the

retina, burns the retina

What is accommodation?

Adjustment of lens for near/far objects

What does it mean to be nearsighted? Draw a ray

diagram. Cannot see far objects

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What does it mean to be farsighted?

Draw a ray diagram.

Cannot see close objects.

What type of lens corrects for near

sightedness? For far sightedness? Why?

Concave- nearsighted (diverges light)

Convex- farsighted (converges light)

Mirrors Why is it when you look at your face in a spoon it is upside down and smaller? How can you position yourself so the image of your face is larger when looking at the spoon? Draw ray diagrams to support your ideas.

A spoon behave as both a concave and convex mirror, depending on the side. See board for diagrams.