PAG 8- EM waves and matter Flashcards
what is the incident ray?
light ray travelling towards a surface
what is the normal line?
line that is perpendicular to a surface
what happens when the incident ray is absorbed?
the light is absorbed and converted into heat energy
what is the angle of incidence?
the angle at which the light enters
what is the angle of reflection?
the angle at which the reflected ray bounces off a surface
what happens when the incident ray is reflected??
-the wave bounces off the surface
-the angle of reflection is equal to the angle of incidence
what is the law of reflection?
the angle of reflection is equal to the angle of incidence
what happens when the incident ray is refracted?
when light travels from a less dense to a more dense medium, the angle of refraction is smaller than the angle of incidence
describe dispersion of light
When white light rays are refracted by a triangular glass prism they are split into a spectrum. Red light is the longest wavelength wave and experiences the least change in velocity, so it refracts the least. Violet is the shortest wave and experiences the greatest change in velocity, so it refracts the most. This is called dispersion.
what are the independant variables for
PAG 8- EM waves and matter?
angle of incidence
what are the dependant variables for
PAG 8- EM waves and matter?
angle of refraction
what are the control variables for
PAG 8- EM waves and matter?
-position of plastic block
-intensity of light
what is the method for PAG 8- EM waves and matter?
- connect the ray box to a power pack in order to produce a slim light ray
- place the Perspex block on the sheet
- use the guidance on the sheet to help you shine the light ray on the block in the correct angle
- use a pencil to make a mark on the sheet where the light ray leaves off the block
- repeat steps 3 & 4 for different angles of incidence
- use a ruler to draw straight line from the point where all the incident rays meet, to each of the marks on the paper
why is it important to place the block in the right place for PAG 8- EM waves and matter?
in order to have an accurate angle of incidence
what safety precautions did you take for PAG 8- EM waves and matter?
-hot light bulb (burns)- grab raybox from sides
-glass light bulb (cut if breaks)- handle with care
-light source (damage eyesight)- don’t look directly into it
what is the conclusion for PAG 8- EM waves and matter?
the angle of refraction is smaller than the angle of incidence as light travels from air to plastic
what are two possible sources of error for PAG 8- EM waves and matter?
-angle of incidence not accurate because of light ray from ray box
-plastic block not aligned well
- marks on paper for refracted rays not accurate
what are two ways to improve my experiment for PAG 8- EM waves and matter?
-light intensity should increase to produce a brighter light ray, use a smaller slit that produces a thinner ray
-try to place the block in the right position
-repeat the process a couple of times for each angle of incidence
