5.4 understanding lenses

The differences between microscope and telescope

Aspects	microscope	telescope
Type of lens	Two high powered convex lenses	A low powered convex lens and a high powered convex lens
Focal  length	F0 < f1	F0 >f1
First image	magnified	diminished
Position of final image	Near point of observer’s eye	infinity
Distance between lenses	Greater than f0+f1	Equal to f0+f1
Linear magnification , M	M = m0 X m1	M = f0 / f1
Condition of eye when using the instrumet	Ciliary muscles are at ease and the eye is relaxed	Ciliary muscles are contracted . eye is strained

SOURCES ;

SUCCESS Physics SPM (page 279)

http://www.google.com.my/imghp?hl=en&tab=wi

5.3 understanding total internal reflection of light

 TOTAL INTERNAL REFLECTION
total internal reflection occur when the condition are :
- light must be refracted from a denser medium to a less dense medium
- the angle of incidence must be greater than the critical angle

APPLICATION

1) periscope
- prisms are used in the construction of a periscope . the image seen through a periscope is upright and the same size as the object .
- the first prism rotates the image by 90` and the second rotates it back to normal

2) single-lens reflex camera
- a single-lens reflex (SLR) camera has a pentaprism which is used to reflect the incoming light to the viewfinder
- this allow the photographer to actually see the light which is entering the lens of the camera

NATURAL PHENOMENON

fish's eye view

rainbow

road mirage

prism periscope

prism binoculars

 optical fibres

 

 

SOURCES ;

SUCCESS Physics SPM (page 263 and 264)
FOCUS SPM Form 4 * 5 Physics (page 245 and 246 ) 

http://www.google.com.my/imghp?hl=en&tab=wi

5.2 understanding refraction of light

 *     i ; incident angle

*  r ; refracted angle

when light travel from a less dense to a denser medium , the ray is refracted toward the normal at point of incidence
when light travel from more dense medium to less dense medium , the ray is refracted away from the normal at point of incidence

snell's law states that sin i and sin r is constant

PHENOMENON

1. shallow swimming pools
 a swimming pool appering to be shallower than it really is , this is due to the lights rays from the bottom of the pool being refracted away from the normal as they  enter the air . when the light rays reach the eye , they appear to come from I which is higher up . so , the pool appears to be shallow .

2. a fish-eye view
a fish or a diver can see objects above the water surface , but the objects on the shore would appear to be up in the air at different positions . due to refraction of light , a fish sees the image of an object at a position that differs from its true positions

3. bent objects in water
the pencil appearing to be bent at the air-water boundary . the light rays from the end of the pencil are refracted at the air-water boundary and bend away from the normal . the image of the pencil under the water appears to be higher than it really is . thu, the pencil appears bent at the surface .

SOURCES ;
http://www.google.com.my/imghp?hl=en&tab=wi
FOCUS SPM Form 4 * 5 Physics (page 230 and 235)

LAWS OF REFLECTION

laws of reflection states that :
(a) the incident ray , the reflected ray , and normal all lie on the same plane .
(b) the angle of incidence is equal to the angle of reflection


APPLICATION

volmeter
- it use a mirror to avoid parallex error

wing mirror
- to enable the driver to see things behind car

microscope
- a plane mirror are used to reflect the image to eyepiece

dentist mirror
- help dentist to see the teeth of a patient

car headlamp
- used as reflectors

SOURCES ;
http://www.google.com.my/imghp?hl=en&tab=wi
SUCCESS Physics SPM (page 238)
FOCUS SPM Form 4 * 5 Physics (page 226 and 227)

transphysics

our group name is transphysics . our group have 6 members which as a following :

nuruljannah binti razak

nur azmina binti hood

mohd faizul bin adnan

mohd nurikhmal bin othman

mohd hasib bin abdul rahim

muhammad syahmi bin mansor