Reflections Flashcards
What type of mirrors are most commonly used?
Most of the mirrors you use are plane mirrors. ‘Plane’ means flat.
What is an example of a distorted reflection?
You can look at your own reflection from a spoon. The reflection is distorted.
How does light travel?
Light travels in straight lines called rays.
What is an incident ray?
An incident ray is the ray coming onto a surface.
How is the angle of incidence measured?
Measure this angle from a line perpendicular to the mirror, called the normal.
What does ‘normal’ mean in physics and maths?
‘Normal’ means perpendicular or at right angles to something.
What is the first step in drawing the incident ray?
Draw the incident ray and the mirror. Sometimes, this is done for you.
How should the incident ray meet the mirror?
Use a ruler to make the incident ray meet the mirror.
How is the normal drawn?
Use a protractor or set square to draw the normal, which is perpendicular to the mirror where the incident ray meets the surface.
What is the angle between the incident ray and the normal called?
This angle is called the angle of incidence.
What is the angle of reflection?
The angle equal to the angle of incidence on the other side of the normal is called the angle of reflection.
What should be included when drawing the reflected ray?
Draw a reflected light ray coming away from the mirror at the angle of reflection, and remember to put an arrowhead on the reflected ray.
How to draw incident ray and reflected ray?
What are ray diagrams?
Ray diagrams show what happens to the light rays during reflection.
What does the law of reflection state?
The angle of reflection is equal to the angle of incidence.
What is a law in physics?
A law is something that always applies.
How can the law of reflection be used in everyday situations?
It can be used with mirrors to see behind us.
How does a driver use a mirror to see a cyclist?
The driver can see the cyclist by using the mirror, which reflects light from the cyclist to the driver’s eye.
What does the ray diagram illustrate in the context of a driver and a cyclist?
It shows how light from the Sun is reflected from the cyclist to the driver’s eye.
What is the angle of reflection in a ray diagram?
The angle of reflection is the angle between the reflected ray and the normal.
How can you identify the angle of reflection in a diagram?
The angle of reflection is always equal to the angle of incidence and is measured from the normal.
What steps should you follow to complete a ray diagram?
- Extend the incident ray until it meets the mirror.
- Draw the normal at the point where the incident ray meets the mirror.
- Measure and record the angle of incidence.
- Draw the reflected ray at the correct angle.
How does light travel from a candle to a person looking at it in a mirror?
Light from the candle travels to the mirror as an incident ray and then reflects off the mirror as a reflected ray, following the law of reflection.
What does the Law of Reflection state?
The Law of Reflection states that the angle of incidence is always equal to the angle of reflection.
What are the key components to include when drawing a ray diagram?
Incident Ray (incoming light)
• Normal (a perpendicular line at the point of reflection)
• Reflected Ray (outgoing light)
• Angle of Incidence (between the incident ray and the normal)
• Angle of Reflection (between the reflected ray and the normal)
How can Marcus use a mirror to see a pencil that rolled under his bed?
He can place a mirror at an angle so that light from the pencil reflects off the mirror and into his eyes.
Why do we see objects in a mirror?
We see objects in a mirror because light rays from the object reflect off the mirror and travel to our eyes.
