Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Transcript of Light
What is light ?
How does light travel ?
Light travels in a straight line
How does shadow form ?
An object (Materials) that does not allow light rays to pass through will form a shadow
Transparent and opaque objects
Light is energy that travels in straight lines called rays that comes from the source of the light.
Light energy which can be seen is called
Main source of light is Sun
We have other sources of light such as light bulb and the moon because the moonlight is the the sunlight that falls on the moon surface and reflects light
Reflection occurs when a light ray hits a surface and bounces off so this reflection makes you see the object.
So when you enter a dark room , you cannot see the objects because there is no light rays falling on any object so you can't see.
Light Reflection on smooth surface
When you stand in front of a mirror,
you can see your image because mirror
is smooth and bright so if light falls, it
will be reflected. This light bouncing is
Reflected light reaches your eyes directly, so you can see your picture. This reflection is known as
Light reflection on rough surface
Try to hold a piece of a white paper you won't see your image , why ?
Paper surface is considered a rough surface not smooth as a mirror as it contains tiny holes; so when light falls on the paper's surface , it reflects and scatters in different directions and what you see is the paper only. This reflection is known as
When light rays enter a new medium at an angle , the speed of the light rays changes , that cause them to bend or change direction
So , when you see the pencil in a water , you will see it broken , but in real its not broken
When light rays enter the triangular prism it splits into the 7 colors called
Red , Orange , Yellow , Green , Blue , indigo , Violet
Complete the following :
1. The prism separates sunlight into ...........
2. Light travels in ......... lines.
3. Light can easily transmit through ....... and ...... materials.
4. ......... and ....... are from spectrum colors.
Write the scientific term :
1. Seven colors which the light is made up of.
2. The change of light rays direction when pass through separating surface between two transparent media.
3. The light energy that can be seen.
4. Materials that doesn't allow light to travel.
Put right or wrong :
1. Object shadow is formed because light travels in curved lines (........).
2. light is a form of energy (........).
3. The glass prism separates the white light into 10 spectrum colors (........).
1. 7 spectrum colors
2. straight lines
3. Transparent , Semi-Transparent
4. Red , Orange , Yellow , green , blue , indigo , violet
1. Spectrum colors.
3. Visible spectrum
4. opaque materials
This video is brought to you by
German University in Cairo
(Visualization and Animation course – Winter 2013)
Choose the correct answer:
1. The nearer object to the light source has the ........ shadow.
a. bigger b. smaller c. fainted
2. All the following examples of transparent materials except ....
a. clear glass b. Book c.clear water
3. The first spectrum color is ........
a. red b. orange c. violet