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Natural sciences

Grade 8

Energy: electricity, heat and light

Module 11

Reflection and refraction of light

  • LIGHT is another common type of energy.
  • You parents or educators would like to have "eyes at the back of their heads" or would like you to believe that they see everything. We know that this is impossible, though, and for a simple reason.

Activity:

To determine the terms and concepts that relate to light

[lo 2.1, lo 2.3, lo 2.4]

Light travels along a straight line.

Light can change direction, though, and this happens in two ways:

  • Refraction
  • Reflection

REFLECTION: We are going to look at reflection as it occurs with mirrors.

When a beam of light arrives at a certain angle, it will be reflected at the same angle.

ANGLE OF INCIDENCE = ANGLE OF REFLECTION

Activity:

To establish concepts relating to reflection [lo 2.4]

Assignment 1:

1. Draw a sketch of a mirror, showing the angle of incidence and the angle of reflection. Use a protractor.

Assessment of the Sketch

Has the sketch been drawn correctly?

[LO 2.4]

Curved mirrors

Curved mirrors have many applications. They enlarge or diminish and distort the image. A curved mirror can be CONCAVE. This will CONVERGE light beams towards a fixed point, the FOCUS.

Other mirrors may be CONVEX . They will cause light beams to DIVERGE (spread apart). This scales down the image. An application of this is evident in the rear view mirror of a motor car or in wing mirrors.

The same effect can be achieved with polished metals.

Assignment 2:

1. Try the following:

Polish the surface of a large serving spoon to get it to shine.

Look at your own image in the concave and on the convex side of the spoon and compare the shape of the reflections.

Draw the differences in the spaces that are provided:

Concave Convex

Draw convergent and divergent beams from the right to add to the following sketches. Get your educator to help you.

Assessment of Sketches

Were you able to complete the sketches correctly?

[LO 2.4]

Assessment

LO 2: Constructing Science Knowledge:

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

This is evident when the learner:

  • recalls meaningful information;
  • interprets information;

2.4 applies knowledge.

Memorandum

Assignment 1:

LIGHT

  • LIGHT is another common type of energy.
  • You parents or teachers would like to have "eyes at the back of their heads" or would like you to believe that they see everything. We know that this is impossible, though, and for a simple reason
  • Light travels along a straight line. Light can change direction, though. This can be achieved in two ways:

REFLECTION:

  • We see this happening in the case of mirrors.

When a beam of light arrives at a certain angle, it will be reflected at the same angle.

Angle of incidence = angle of reflection

CURVED MIRRORS

  • Curved mirrors have many applications.
  • They enlarge and distort images.
  • A mirror could be C ONCAVE
  • It will CONVERGE light beams towards a fixed point, the FOCUS.
  • Other mirrors may be CONVEX .
  • They will cause light beams to DIVERGE (spread apart)
  • This scales down the image.
  • An application of this is evident in the rear view mirror of a motor car or in winged mirrors.

  • Try the following:
  • Polish the surface of a large serving spoon to get it to shine.
  • Look at your own image in the concave and in the convex side of the spoon and compare the effect of the shape on the reflections.

Draw the differences in the spaces that are provided:

Questions & Answers

how can chip be made from sand
Eke Reply
is this allso about nanoscale material
Almas
are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where is the latest information on a no technology how can I find it
William
currently
William
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
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