Term+2+Issues+in+Teaching+and+Learning+Science


 * Learning points**

Firstly, we learnt how to draw a light ray diagram. I've always have the conception that light must be reflected at 90 degrees. However, this lesson made me realised my mistake! The light ray reflection follows a strict principle of i = r, which basically means that the angle of incidence equates to the angle of reflection.Furthermore, I have also discovered that the image formed by a normal plane mirror is always laterally inverted and the features, including distance of the objects and the mirror is always the same. Also, we have to learn to apply these concepts like determining the height of the mirror from the reflection ray diagram. Since the ray follows a strict rule of i = r, the mirror must be at least half the height of the person in order for one to view his full body. This was an interesting fact that I have learnt from learnt from the worksheets and have actually tried it in class where there is a mirror at the back! Physics is more focused on doing hands on experiments and understanding the concepts rather than plain memorising so that the knowledge will be deeply ingrained in your memory and can be even be applied in everyday activities.The most challenging part about reflection is the convex and concave mirrors and how the image are formed. This part is exceptionally confusing and difficult in my opinion as I simply cannot visualise the image in my head. This is because my weakness is in drawing, measuring and especially visualizing. I find these very tedious and furthermore, I just cannot seem to visualize things from another angle. Hence, I am not really good at drawing diagrams, especially ray diagrams. Even after looking at diagrams, I still encounter some difficulties trying to understand these concepts. I will have to do more revision on this and try my best to understand them. Meanwhile, I can only memorise them.In addition, we did lab experiments on this topic. We were given a light box and we are supposed to test out the angles of incidence and reflection for ourselves using the plane mirror. We later moved on to using the concave and convex mirror, which resulted in a diverging ray but still following the theory of i = r. We started on the experiments with our trace sheets ready before inserting the chip to focus the light into one thin beam. Later on, we position the beam of light exactly at the line we have drawn on the trace sheet before using the mirror to reflec the ray off. It was an enriching lab lesson that is a stark contrast from chemistry, where we normally interact with chemicals and exposes us to a hand-on experiment of testing i=r theory.



Light is the form of energy that enters our eyes and enables us to see things around us. Light can either be directly obtained from a luminous source or reflected off a non-luminous source into our eyes.So basically, when a ray of light strikes off any surface, it changes its direction of travel as laws of reflection are being applied. Light can strike on all types of surfaces and the terms used in reflection will be constant.
 * Quick Summary of what I have learnt: **

- Incident Ray: The ray of light that strikes the surface - Reflected Ray: The ray of light that is reflected off the surface - Normal: A line that is perpendicular to the surface at the point of incidence - Point of incidence: Point where the incident ray strikes the surface - Angle of incidence: Angle between the incident ray and the normal - Angle of reflection: Angle between the reflected ray and the normal

The normal, incident ray, the reflected ray and the point of incidence will lie in the same plane. The angle of incidence is equal to the angle of reflection. There are two types of reflection: - Specular Reflection : Mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction. - Diffused Reflection : Reflection of light such that the incident ray may be scattered in all directions. The image in the mirror is known as virtual image. The image formed by a plane mirror... - has the same size as the object - is as far behind the mirror as the object is in front of the mirror - has the same orientation as the object - is laterally inverted
 * 1st Law of Reflection**
 * 2nd Law of Reflection**

//**__Refraction__**// When light strikes a reflecting surface, most of the light is reflected. However, some light will be absorbed by the surface. For instance, at a air- glass surface, light is reflected off the surface and partially transmitted through the medium. When light is transmitted through the medium, it will bend as it travels from medium with different optical density So basically, the higher the optical density of a medium, the lower the transmittance, thus the greater the refraction of light in it.When a ray of light travels from an optically less dense medium into an optically dense medium, it will be refracted towards the normal as the speed of light will decrease when it travels in the optically denser medium. However, when a ray of light travels from an optically denser medium into an optically less dense medium, it will be refracted away from the normal. .