Light and Shadows
Explore how light travels in straight lines, what happens when it hits different materials, and how shadows are formed.
What You Need to Know
Key Concept Diagram
Light travels in straight lines from its source (the Sun, a torch, a lamp).
Opaque objects block light completely, forming a shadow on the other side.
Transparent objects let nearly all light through; translucent objects let some light through.
The size of a shadow changes depending on the position of the light source relative to the object.
Key Vocabulary
opaque
A material that does not let light through, forming a clear shadow.
transparent
A material that allows almost all light to pass through (e.g. clear glass).
translucent
A material that lets some light through but scatters it (e.g. frosted glass).
shadow
A dark area formed when an opaque object blocks a light source.
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
Why does an opaque object create a shadow?
Question 2
What happens to a shadow when the light source moves closer to the object?
Question 3
Frosted glass is an example of which material type?
Key Concepts Summary
- ●Light travels in straight lines from its source (the Sun, a torch, a lamp).
- ●Opaque objects block light completely, forming a shadow on the other side.
- ●Transparent objects let nearly all light through; translucent objects let some light through.
- ●The size of a shadow changes depending on the position of the light source relative to the object.