Science

Sources of Light

• A torch
• The sun A candle                          Normal=measured from a line at 90 degrees
• A match
• Car headlight
• A star

Light travels at 300,000,000m per second. You can tell that light travels faster that sound as during a thunder storm you see the lighting first than you hear the thunder but they actually happen at the same time but when your a distance away you will have a difference.

Objects that create their own light are called luminous objects but some objects dont create their own light so how do we see them? As the light reflects off them and into our eyes.

Angle of incidence=the angle between the normal and the light hitting the mirror

Angle of reflection=the angle between the normal and the light leaving the mirror

Opaque objects                                                                                    

• Book                                                     
• TV
• Bag
• Wall

Translucent objects

• Frosted Glass
• Shower curtain
• Tracing paper

Transparent objects

• Glass door
• Window
• Air

Uses of mirrors

• Refelctions 
• To show a clear image
• Car mirror
• Dentist mirror

Refraction means the change of the direction of light. When light enters a glass prism it speeds up which causes it to change direction closer to the normal. When you put a pen in water the light rays slow down which cause the pen to look odd and out of shape.

Angle of incedence=the angle from the ray to the normal

Angle of refraction=the angle from the line in the glass to the normal

Way to find out the depth of water

Apparent depth=0.75*real depth

Real depth=0.75/ apparent depth

Filters

Green filters absorb every other colour except green, yellow fliters absorb every other colour except yellow.

Spectrum

• Richard=red
• Of=orange
• York=yellow
• Gave=green
• Battle=blue
• In=indigo
• Vain=violet

When you can see a rainbow its because the raindrops act as ting little prisms as the light from the sun is white it goes through the rain drops and relflects out as a spectrum.

Endoscope

An endoscope is a tube with a light and a video camera on it. It is used to inspect peoples organs or tissues when a ct scan inst appropriate.