Activity |
Key teaching pointsWhat do I want my students to learn? |
Demonstration or other type of practical activity? Key reason for choice?Comments?What else do I need to do? |
10.1 |
Shiny spoon is like a convex mirror on one side and a concave mirror on the other side.Image in a concave mirror at different distances.Image in a convex mirror at different distances.Size of image? Erect or inverted? Real or virtual? |
Teacher-directed activity, but every student needs to try out the activity.Quickest and most effective if everyone has a shiny spoon.No changes with convex side, but everyone needs to see two types of image with the concave side. |
10.2 |
Concave mirror converges rays of light from the Sun to a point. Very bright light at this point – energy delivered to one spot enough to cause damage or burning!Distance from mirror centre to point is roughly the focal length of the mirror.Conventions: Drawing curved mirrors and rays; rays from a distant object are parallel. Arrows are from object.Terminology: pole P, principal focus F, focal length f, principal axis, centre of curvature C. |
Demonstration. Safety: Potential hazard from bright light reflected into eyes, so I will do this.Draw the mirror, parallel rays from Sun and converging rays reflected from mirror to introduce drawing conventions and terminology.May be difficult to show that the image of the Sun is inverted! Leave to next activity? |
10.3 |
Properties of images in a concave mirror for six different object positions. Position, size and nature of image.Using the terminology and conventions. |
Demonstration. Timing issue and ensures correct procedures and results.Quite lengthy and technical, so needs lots of questions and student involvement to keep attention. Different student ‘assistant’ for each situation.Issues about viewing images – everyone needs to see each image. |
10.4 |
Ray diagram construction for each of six object positions from activity 10.3 to illustrate use of rules for constructing ray diagrams. |
Demonstration. Timing issue and ensures correct procedures and results.Quite lengthy and technical, so needs lots of questions and student involvement to keep attention. Different student ‘assistant’ for each situation.Needs immediate follow-up by students drawing own diagrams. |
10.5 |
Images in a concave mirror are always virtual, diminished and erect. |
Teacher-directed activity with a convex mirrorfor each group. Enough mirrors for this so not resource issue. More effective and quicker for everyone to see this way. |