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
- Frosted Glass
- Shower curtain
- Tracing paper
- Glass door
Uses of mirrors
- 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
Green filters absorb every other colour except green, yellow fliters absorb every other colour except yellow.
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.
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.