Higher:
Is able to design and build a periscope
Middle:
Can describe how a periscope works and when it can be useful
Lower:
Knows what a periscope is
Lesson Recap Starter: Think back to the last lesson. Name the two types of mirrors.
Lesson Starter: Look at the starter slide - ask the big question to the children - how is it possible to look across/over the water using a periscope? How do they think it works?
Presentation - Starter Slide.
Explore presentation on periscopes, how they are used and what they are useful for. Ask children questions as suggested.
Key Concept:
During this unit, each lesson contains a key concept question housed in the '30 Second Challenge' slide. To help children master this content so the knowledge moves from their short term memory to their long term memory, at the beginning of the follow on lesson the question from the previous lesson is revisited.
The questions covered during this unit include:
1. Explain how a shadow is formed.
2. Is the moon a source of light? Is the Sun a source of light?
3. Name the two types of mirrors.
4. Explain how a periscope works.
5. What is a reflective surface? How can reflective surfaces be used?
6. Write a persuasive sentence to convince your friend why it’s important to wear a pair of sunglasses is so important.
Presentation
Expert Film: Mike Linley discusses what a periscope is and how it is used.
Periscopes are used in submarines - what are submarines?
How we deliver the Gatsby Benchmarks:
2 - Learning from career and labour market information: Pop along to Developing Experts career’s zone to find out about jobs in your area.
4 - Linking curriculum learning to careers: This unit showcases careers that relate to light. Access our 360° virtual work tours.
7 - Encounters with Further and Higher Education: Pop along to Developing Experts career’s zone to find out about training providers in your area.
Presentation - Expert Film.
Make Your Own...Periscope!
The Handout and the Mission Assignment video contain the instructions students will need to complete this Mission Assignment.
If you do not have two mirrors that are 6 cm x 4 cm, they can be cut from a plastic mirror so they fit into the periscope. For safety reasons, we advise that you do this yourself, as opposed to letting the students cut the pieces of mirror.
Once children look through the viewer, they should be able to see over table tops etc and spy on one another! Give it a go!
Make a Periscope
Cardboard (or juice cartons)
Duct tape
Scissors
Small mirrors
Paints, papers, etc. for decoration.
Handout
Handout - Draw the line of sight for a periscope and explain how it works.
(choice of two handouts)
Quiz
With their talk partners, the children are to go through the quiz at the end of the presentation and answer the questions.
Handout
Quiz in presentation
Can children identify how a periscope works?
Can children explain how light reflects in a periscope?
Can children think of ways a periscope may be useful?
When designing their periscope designs do children realise the importance of ensuring the angle of reflection is set at the right angle?
Quizzes in pupil zone.
Unit knowledge organiser and test in unit documents area.
A periscope can be used to...
A periscope works by...
The Science Behind the Science
A periscope is an instrument consisting of a tube that is attached to a set of mirrors or prisms. The individual who is observing through a periscope can see things that are otherwise out of sight. Periscopes let you see over the top of things. This could be a tall wall or a fence that is big enough to look over. Did you know that you can also use periscopes to see around corners?
They were first used in submarines around 1860. Sailors used these to see above the water. Back in the day, soldiers used them to look over trenches without having to pop their heads out and put themselves in further danger. They are still used in submarines and tanks today.
How are they used? Well, a basic periscope has a long tube with a mirror at each end. Each mirror is fitted at an angle of 45 degrees so that they are facing one another. Initially, the light will hit the top mirror at an exact angle of 45 degrees. This same light will reflect away at the same angle. It will travel along the tube and bounce to the bottom mirror. When this reflected light hits the second mirror, it is reflected once again at an angle of 45 degrees into your eye. This is how you can see. Here is a top tip: light is always reflected away from a mirror at the same angle that it hit.
Mission Assignment: Simple mirrors will let you see around a corner but to see above an object, two mirrors are required. They must be aligned in a certain way for this to work. Therefore, they suggest a 45º angle. If you look at an angle that is vertical (90º), the horizontal plane would be 0º and the angle in between would be 45º. If you look up vertically (90º) at a mirror that is placed at 45 degrees, then you will see whatever is in front of the mirror at 0º. This is how it generally works. If the mirror was at 75º, you would look up at the sky. If the angle was at 30º, you would look at the water.
Notice that light is reflected from surfaces.
Forces and Energy: the study of energy, its origin, storage and transfer and the work it can do; the study of forces; the application of scientific understanding through inventions and machines.
Looking for patterns.
Recording findings using simple scientific language, drawings, labelled diagrams, keys, bar charts, and tables
Grade 3 Light
