Summary
Light is a form of energy that allows us to see and travels in a straight line. Shadows are formed when light is blocked by an object.
- Light — a form of energy that enables us to see. Example: Light from a lamp helps us see in a dark room.
- Straight Line Travel — light travels in a straight path. Example: A laser beam travels in a straight line.
- Reflection — light is reflected into our eyes, allowing us to see objects. Example: We see the moon because it reflects sunlight.
- Shadow — formed when light is blocked by an object. Example: A tree blocking sunlight creates a shadow on the ground.
- Light Source — the origin of light that can create shadows when obstructed. Example: The sun is a natural light source.
- Screen — a surface where shadows are cast. Example: A wall can act as a screen for shadows.
- Size of Shadows — can be changed by moving the object or screen. Example: Moving an object closer to the light source makes its shadow larger.
Exam Tips
Key Definitions to Remember
- Light is a form of energy that enables us to see.
- Shadows are formed when light is blocked by an object.
Common Confusions
- Thinking light can bend around objects to form shadows.
- Believing shadows are objects themselves rather than the absence of light.
Typical Exam Questions
- What happens when light is blocked by an object? A shadow is formed.
- How can you make a shadow larger? Move the object closer to the light source or the screen closer to the object.
- Why do we see objects? Because light is reflected into our eyes.
What Examiners Usually Test
- Understanding of how shadows are formed.
- Ability to explain how the size of a shadow changes.
- Knowledge of light's properties, such as traveling in a straight line.