THE PLANE MIRROR

Students investigate the reflection of light of a plane mirror. They use their findings to locate the image formed by a plane mirror. They predict the minimum sized mirror that will just enable the whole face to be seen as the image. This is checked with a plane mirror a a piece of a paper with a window cut in it to size. 

What you need ?

Light/Ray box, Plane mirror from ray box kit, Protractor, 30 cm ruler, Plane mirror with dimensions greater than half the width and height of the face. A mirror tile is suitable, Piece of paper as big as the mirror, Scissors  

EXPERIMENT : THE EYE

Students investigate how the eye locates images and the optical illusions that occur if light changes dirEctions after leaving the source. Apparent size is related to the angle subtended at the eye by the an object. Why objects are seen to have colour and fatigue of the eyes ability to sense the same colour are investigated. Lastly, students find their blind spot when one eye is open. 

What you need ?

Ray/light box kit, Large piece of matt black paper or material, Red, white, yellow, green and blue squares of cardboard, Red filter, Spectroscope    

PRISM

Newton's decomposition of sunlight with a prism

Isaac Newton was born the year Galileo died. He graduated from Trinity College, Cambridge, in 1665, then holed up at home for a couple of years waiting out the plague. He had no trouble keeping himself occupied.

The common wisdom held that white light is the purest form (Aristotle again) and that colored light must therefore have been altered somehow. To test this hypothesis, Newton shined a beam of sunlight through a glass prism and showed that it decomposed into a spectrum cast on the wall. People already knew about rainbows, of course, but they were considered to be little more than pretty aberrations. Actually, Newton concluded, it was these colors — red, orange, yellow, green, blue, indigo, violet and the gradations in between — that were fundamental. What seemed simple on the surface, a beam of white light, was, if one looked deeper, beautifully complex.

DISTANCE, DISPLACEMENT, SPEED AND VELOCITY

Distance, Displacement, Speed and Velocity.

Distance and Displacement.

Distance : Total length of distance travelled. Distance is called as scalar quantity since it has magnitude and no direction. To better differentiate distance from displacement is that distance is the long way from the initial point to the final point.

Displacement : The total distance travelled in a specific direction. Displacement is a vector quantity since it has magnitude and direction. Displacement a.k.a. shortcut is the path with the shortest length that links the initial point to the final point.

Still confused ? Here's a simple example.

Distance : I tell you to walk 5m, then 3m. Where are you ?

Displacement : I tell you to walk 5m backwards, then 3m to the left. Where are you now ?

Obviously, in both situations, you are in different places and this is due to the direction you took. In distance, you had the freedom to choose which ever direction you want but in displacement, you followed the given directions. But when in comes to calculations, distance is the total length of the whole diagram while displacement is the length/shortcut between the initial point and the final point. Faham ?

Speed and Velocity.

Speed : The rate of change of distance. A scalar quantity since it has no direction.

Speed, v = Total distance travelled, s (m)

             Time taken, t (s)           

Velocity : The rate of change of displacement. A vector quantity since it has both magnitude and direction.

Velocity, v = Displacement, s (m)

                   Time taken, t (s)  

Alright, that is all for now. The next post will be about average speed and average velocity, acceleration and deceleration. Do comment for any wrong facts or if you simply do not understand.

INTRODUCTION

Well, since the whole class has not decide on what to do, let's make this blog educating and worthwhile going online for. We'll be educating you guys on Physics. We'll blog about all the chapters in both Form 4 and Form 5. You can click on the links available at the Topics & Sub-Topics on the right side of the blog.