Light in my eyes

Light in my eyes

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about observing reflected light.
diagram of mirror and paper for science investigation about reflected light

Instructions

  • You will need a partner to help you with the task.
  • Place a mirror so it sits flat against a wall.
  • Make a mark halfway along the mirror.
  • Put a piece of paper on the floor in front of the mirror.
For each diagram:
  1. Put the torch at a similar angle to how it is drawn and shine it at the mark on your mirror.
  2. Ask your partner to hold up a ruler on the other side of the middle line. Move it sideways until the light shines on it.
  3. On each diagram, mark with a cross where the ruler is.
  4. On each diagram draw a line from the mirror to the cross to show where the reflected light goes.
     

Question Change answer

a)  i)  Put the torch at a similar angle to how it is drawn and shine it at the mark on your mirror. 
Ask your partner to hold up a ruler on the other side of the middle line. Move it sideways until the light shines on it.
  1. Mark with a cross where the ruler is now.
  2. Draw a line from the mirror to the cross to show where the reflected light goes.

Question Change answer

a) ii)  Put the torch at a similar angle to how it is drawn and shine it at the mark on your mirror. 
Ask your partner to hold up a ruler on the other side of the middle line. Move it sideways until the light shines on it.
  1. Mark with a cross where the ruler is now.
  2. Draw a line from the mirror to the cross to show where the reflected light goes.

Question Change answer

a) iii)  Put the torch at a similar angle to how it is drawn and shine it at the mark on your mirror. 
Ask your partner to hold up a ruler on the other side of the middle line. Move it sideways until the light shines on it.
  1. Mark with a cross where the ruler is now.
  2. Draw a line from the mirror to the cross to show where the reflected light goes.

Question Change answer

b)  Shine the torch at the mirror and find out where the torch needs to be to get the light to shine back on your face. Draw where the torch is on the diagram below.

Question 1Change answer

c)  Write a sentence describing any pattern that you have noticed about the diagrams you have drawn of the torch and its light.
Task administration: 
This task can be completed with pencil and paper or online.
 
Equipment

Mirror; torch or laser pointer; a large piece of paper with a line down the centre; ruler; sticky tape (optional).

NOTE: A torch with a narrow beam is preferable because it is easier to complete question a) accurately.

  • The task assesses students' ability to observe reflected light, and is an important precursor for understanding the predictable ways that light is reflected from smooth surfaces, and that we see an object when the light comes into our eyes.
  • Students work in pairs to complete this task.
  • Drawing a centre line on a piece of paper in front of the mirror will help students to see the reflected angle. Marks could be made on the floor or paper to indicate the different positions from which to shine the torch. Students could also draw the lines of the reflected light path on the piece of paper before they add to the diagrams.
Copyright: 
Graphics (c) NZCER
Level:
4
Curriculum info: 
Science, Investigating in science, Physical World
Keywords: 
physical inquiry, light, reflection, pattern seeking
Description of task: 
Task: investigate reflection of light using a torch and mirror. Assessment focus: angle of reflection.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
 
Capability: Gather and interpret data
This resource provides opportunities to discuss looking for patterns in the data collected.
Science capabilities: 
Gather and interpret data
Answers/responses: 

a)

i)          ii)          iii)     

b)

c)

Best answer

The angle of the light from the torch equals the angle of the reflected light. (The response identifies the pattern and includes some notion of measurement.

Some students may even carry out the measuring.)

Partial answers

The greater (smaller) the angle from the centre line you shine the torch, the greater (smaller) the angle of the reflected light beam is on the other side. (The response identifies the pattern.) Or another response that shows this pattern has been noticed.

When the torch is shone at right angles / straight on to the mirror, it reflects back along the same pathway. (The response refers to only one of the observations.)

The following resources include some activities for exploring reflected light:

  • Ministry of Education (2001). Building Science Concepts book 10, Light and Colour. Wellington: Learning Media.
  • Ministry of Education (2001). Building Science Concepts book 11, Seeing Colours. Wellington: Learning Media.
  • Ministry of Education (1999). Making Better Sense of the Physical World. Wellington: Learning Media.
The New Zealand Curriculum Exemplar Periscopes, although it exemplifies Level 3 work, provides ideas for exploring reflected light within an interesting context, and includes questions for teachers to ask. 
 
ARB resources: