SHS1 Physics · Semester 2 Week 3: Waves

Lesson notes

Learning Objectives

Indicator: 1.2.2.LI.4 - Establish the relationship between the real depth, apparent depth and the refractive index.

By the end of the lesson, learners can:

Define real depth and apparent depth in their own words with reference to a medium such as water.
State the relationship between real depth, apparent depth and refractive index as n = real depth / apparent depth.
Calculate the refractive index of a medium given the real depth and apparent depth of an object in it.
Calculate the real depth or apparent depth of an object when the other two quantities are known.
Explain, using the concept of refraction, why objects in water appear shallower than they actually are, and apply this to everyday observations.

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Curriculum details

Strand: Energy (Strand 2)
Sub-strand: Waves (2.2)
Content standard: 1.2.2.CS.3 - Demonstrate knowledge and understanding of refraction. 1.2.2.LO.3 Explain refraction and recognise its relevance in different media.
Indicator: 1.2.2.LI.4 - Establish the relationship between the real depth, apparent depth and the refractive index.
Suggested placement: Semester 2, Week 3 (Week 23 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
Curriculum reference: NaCCA curriculum document, p. 57

Exemplars (from the NaCCA curriculum)

Collaborative learning: Put learners into groups of mixed abilities and let them watch a simulation of how refraction causes apparent displacement of objects at the bottom of a pool of water. Learners must come out with the relationship between the real depth, apparent depth and the refractive index.
Explore contributions of vulnerable groups in the class.
Assessment (1.2.2.AS.4). The document marks these depth-of-knowledge levels for this indicator: Level 3 Strategic reasoning; Level 4 Extended critical thinking and reasoning.
Teaching and Learning Resources:
- Bowl/ basin
- Stick
- audio-visual
- internet projectors
- Interactive virtual laboratory