4.PS.4-2_Topic 2 Lesson 3-Light Waves

​Topic 2 Lesson 3-
Light Waves

By Jessica Freeman

BrainPop- Light (4th grade)

By Shayla Roberson

Multiple Choice

•Most objects give off their own light.

• True

• False

Open Ended

List one natural and one man-made light source below.

Open Ended

look around your house. Find one light source and show it on camera. When you show the light source, select list it below.

Multiple Choice

1. If an object allows almost all light to pass through it then it is...

• opaque

• transparent

• translucent

• cold

Multiple Choice

The windows that you can easily see through is transparent.

• true

• false

Multiple Select

A _________ object lets some light pass through it.

• transparent

• opaque

• translucent

Open Ended

Name an item that you think is translucent

Multiple Choice

•An _________object lets no light pass through it.

• opaque

• translucent

• transparent

Multiple Choice

A block of wood is opaque.

• true

• false

Multiple Choice

A clear window is opaque

• true

• false

Multiple Choice

If you were building a house in Alaska (where it can be daylight for months!), what type of material would be best to cover your windows with that would help keep the Sun out of your room so you can sleep?

• transparent material

• translucent material

• glass material

• opaque material

Multiple Choice

Your grandma has plants in her kitchen. They need lots of light! What type of windows should she have installed that will be best for her indoor garden?

• transparent material

• translucent material

• glass material

• opaque material

Multiple Choice

The windows that you can easily see through is transparent.

• true

• false

Multiple Choice

What is the only form of energy we can see?

• Prism

• Light

• Mirror

Multiple Choice

Which light source causes shadows in the outdoor environment?

• The sun

• The light bulb

• The house

• The school

Open Ended

A shadow is a place where light _________________

Multiple Choice

Shining a flashlight on a flat mirror proves that light can

• pass through objects.

• only travel in a straight line.

• be reflected.

• be absorbed by the mirror.

Multiple Choice

What word is used to describe light as it strikes a smooth, shiny surface and bounces off?

• shadow

• energy

• reflection

• wave length

Multiple Select

Light travels in ---------

• Wave

• Straight line

Multiple Choice

When light bounces back it is _____

• Reflected

• Refracted

• Absorbed

• Optical Density

Multiple Choice

When light bends it is ______

• Reflection

• Absorption

• refraction

• optical density

Multiple Choice

Why does the straw appear to be bent?

• light is reflected

• light is absorbed

• light is turned

• light is refracted

Multiple Choice

Light traveling through the air moves in a straight line. An object viewed through water looks different because light rays that travel through water are –

• bent.

• bounced.

• reflected.

• absorbed.

Multiple Choice

What is happening in this picture?

• Reflection

• Refraction

Multiple Choice

Refraction is when light...

• Bounces

• Transmits

• Bends

• Absorbs

Multiple Choice

The following is a picture of what type of mirror?

• Convex Mirror

• Concave Mirror

• Plane Mirror

• Flat Mirror

Multiple Choice

Which of the mirrors is used as rearview mirror in vehicles?

• Concave

• Convex

• Plane

Multiple Choice

Convex mirrors cause light to spread out.

• True

• False

Multiple Choice

A ___ lens makes objects appear bigger.

• concave

• convex

• prism

• flat

Multiple Choice

Why does a banana appear to be yellow?

• When white light strikes a banana, all colors of light except for yellow are reflect it. Yellow light is absorbed from the banana. You see the banana yellow.

• The seven colors are absorbed.

• When white light strikes a banana, all colors of light except for yellow are absorbed. Yellow light is reflected from the banana. You see the banana as yellow.

• When white light strikes a banana, the yellow and all the other colors are reflected.

Multiple Choice

Which colors make up white light?

• Red, Orange, and Yellow

• All colors

• Reds and Violets

Multiple Choice

Which color absorbs all light?

• White

• Black

• Orange

• Green

Multiple Choice

The color you see is the color that is ___.

• reflected

• absorbed

​Measuring Light

• We measure light by 3 different properties:

  • Brightness

  • Color

  • Visibility​

​Color

• ​Light, or "white light", is made up of ALL colors of light mixed together.

• ​If white light passes through a prism, it can be separated into all of the colors.

• ​Those colors are red, orange, yellow, green, blue, and violet -- the colors of the rainbow!

​Brightness

• ​The intensity of light is how we measure how much light we can see.

• ​The closer the source of light is, the brighter it is.

  • ​Think of a flashlight. If you hold it up close to your face, it hurts your eyes to look at.

• ​The farther away the source of light is, the less bright it is.

  • ​If someone with a flashlight is far away from you, you can still see the light, but looking at the flashlight won't hurt your eyes as much.

​Visibility - an object's ability to be seen

• ​In order for us to see an object, it has to either give off its own light or reflect light.

  • ​What are some objects that gives off their own light?

• ​This means everything that does not make its own light reflects light to be seen.

  • ​That even means us! Think about it, if we are in a dark room, you can't see another person or objects. This is because there is no light for us to reflect.

​What happens when light hits objects?

• ​Light can do 3 things when it hits an object. It can be:

  • ​Reflected

  • ​Refracted

  • ​Absorbed

​Reflection

• ​When light is reflected, it bounces back from a surface.

• ​This is how we see objects that don't make their own light - it bounces off the surface/object and reflects light into our eyes.

• ​When light hits a shiny or smooth surface, like a mirror or still water, it is reflected and can show us a reflection very similar to the object seen.

• ​The color of the light that is reflected is the color we see. For example, something red only reflects red light.

​Refraction

• ​When light is refracted it passes from one type of material and changes direction.

• ​A great example of this is a magnifying glass. When light passes through, it changes directions, which lets us see a much bigger version of what we are looking at.

​Absorption

• ​When light is absorbed it does not reflect or pass through the object. It remains in the material as a form of energy,

• ​The colors of objects are determined by the light that is not absorbed and then reflected for us to see. All other colors of light striking the object are absorbed.

  • ​For example - if you are wearing a blue shirt - white light strikes your shirt. All colors EXCEPT for blue are absorbed. Blue is reflected to our eyes.

Multiple Choice

What was this lesson about?

• Light

• Fractions

• Space

• The Solar System

Open Ended

What are the 3 properties that we look at to measure light?

Open Ended

What happens when light hits objects? (Think about the 3 things that light can do.)

​Check your answers!

1. ​What was this lesson about? SPACE

2. ​What are the 3 properties that we use to measure light? BRIGHTNESS, COLOR, VISIBILITY

3. ​In our "Color" slide, we talked about what happens to light when it passes through a prism. What happens to that white light? IT SEPARATES INTO ALL OF THE OTHER COLORS.

4. ​What happens when light hits objects? IT CAN BE REFLECTED, REFRACTED, or ABSORBED.

Refraction, Reflection, Absorption

Behavior of Light

Multiple Choice

When a person walks into the water at the beach, it appears that their feet are separated from their legs. This occurs because the light waves bend as they pass between air and the water. This is an example of...

• reflection of light

• transmission of light

• absorption of light

• refraction of light

Multiple Choice

When waves bend due to a change in their speed as they pass from one medium to another, we are referring to ...

• reflection

• transmission

• absorption

• refraction

​- The bending of waves due to a change in speed

​

- Sound waves are refracted when changing mediums (solids to liquids to gas) or travel through different temperatures

​

- Light travels through a material and changes speed and is bent​

​

Ex: pencil in water​

​Refraction

​

Multiple Choice

A student looks at a shiny object and sees themselves. What is happening to MOST of the light that is hitting the shiny object?

• The light is being absorbed

• The light is being reflected

• The light is being transmitted

• The light is being transmitted

​ Reflection

​- The bouncing back of a wave when the wave hits an object

​- An echo is a mechanical wave reflecting into the medium from which it came

​- Light waves bounce off a surface

ex: light on shiny surfaces and mirrors ​

Multiple Select

In what ways do waves change their behavior when they encounter a new medium?

• refraction

• reflection

• absorption

• cancellation

Light: What is it?

A form of energy we can see

Multiple Choice

Light is energy we can touch.

• True

• False

Because of Light - Objects can be seen when they

• Give off light

• reflect light (bounce light off the surface)

Multiple Select

What are the two ways objects can be seen?

• It gives off light

• It smokes.

• It reflects light.

• It rusts.

Light Travels: Straight Line

• Light travels this way until it hits something

Multiple Choice

Light always travels in a strait line, even when it hits something.

• True

• False

Light Travels: Reflection

• Light bounced off an object with a smooth surface.

• Light will reflect at the same angle that it hit the reflective object.

• Rough surfaces scatter light instead of reflecting it.

Multiple Choice

Light reflects off a smooth surface the same way it reflects off a rough surface.

• True

• False

Light Travels: Absorption

• Light is absorbed (taken in) by an object.

• The object gets warmer as the light changes to heat (thermal) energy.

Multiple Choice

When light gets taken in by an object, it is

• absorption

• reflection

• refraction

• transmission

Multiple Choice

The more light an object absorbs, the more heat energy it will make.

• True

• False

Light Travels: Refraction

• Light transmits through an object.

• It changes direction when it passes from one material (medium) to another.

• It is the bending of light.

Multiple Choice

When light goes from one medium (material) to another, it will bend. This is called

• absorption

• reflection

• refraction

• transmission

Seeing Color

• Different materials absorb more light of certain colors and reflect more light of other colors.

• Colors are the way we see reflected light.

Multiple Choice

The colors we see are the light that gets reflected off of the object.

• True

• False

To See Color: Black

• The object absorbs most colors of light

• Light energy changes to heat energy

Multiple Choice

What color is only seen when most of the colors of light are absorbed by an object?

• black

• green

• orange

• white

To See Color: White

• The object reflects most colors of light

• Not as much chance for light energy to change to heat energy.

Multiple Choice

What color is only seen when most the colors of light are reflected off the object?

• black

• green

• orange

• white

Multiple Choice

Which of the following is an artificial light source?

Multiple Choice

How does a light bulb work?

• A wick inside the bulb is burned

• An electric current is passed through a filament.

• White light is passed through a prism

• Ambient light is reflected by a small mirror.

Multiple Choice

What can you infer about the environment the anglerfish lives in?

• It must be extremely bright.

• It must be extremely dark

• It must be filled with other fish.

• It must be empty of other fish.

Multiple Choice

What device produces light by running an electric current through a gas?

• An incandescent light bulb

• A flashlight

• A neon sign

• A prism

Multiple Choice

What could you use to split white light into its component colors?

• A flashlight

• A capacitor

• A light bulb

• A prism

Multiple Choice

Why does refraction occur?

• Light travels through different materials at different speeds

• Different colors of light travel at different speeds.

• Different materials physically twist light around.

• Light from different sources travels at different rates.

Multiple Choice

Only a minute portion of the electromagnetic spectrum can be seen with the human eye. In this context, what does "minute" mean?

• Colorful

• Large

• 60 Seconds

• Small

Multiple Choice

When you look at your teacher's face, how can you see it?

• Light reflects off of her face.

• Her face emanates light.

• Light refracts through her face

• Her face emits electromagnetic radiation.

Multiple Choice

Light can behave as both a ______ and a _______.

• Ray; beam

• Wave; particle

• Natural source; unnatural source

• Refraction; reflection

Multiple Choice

Why does the light we see from stars take thousands of years to reach us?

• Because the light is slowed down by gases in outer space

• Because the light is reflected off of other stars

• Because the stars are very far away

• Because light travels very slowly