physics Flashcards
Normal
90 degrees from the surface
incident ray
ray of light going toward the surface
reflected ray
ray light coming away from the surface
i°
angle of incidence
r°
angle of reflection
law of reflection
angle of I° is equal to r°
specular reflection
light meeting the surface in one direction is all reflected in one direction.
diffuse scattering
When light is reflected off a surface in all directions.
density
mass / volume
refraction
process which a wave changes speed and direction when entering a different density.
refraction into denser material does what to the ray
it bends towards the normal
refraction into a less dense material does what to the ray
it bends away from the normal
spectrum of light
A series of similar waves arranged in order of wavelength or frequency.
frequency
The number of waves produced each second. measured in hertz (Hz).
dispersion
Spreading out of the different wavelengths of light, caused by refraction of light as it passes through a prism.
what are the secondary colours of light?
cyan (light blue) , yellow, magenta (reddish pink)
why are objects coloured?
because the object absorbs all light waves except its own colour.
what is the relationship between speed, distance and time? (the triangle)
distance / (speed x time)
speed
a measure of how fast an object is moving. m/s
distance
Numerical description of how far apart two things are. m
time
how long an event lasts, s
unit
the measurement of a quantity.
what is the relationship between pressure, force and area. (triangle)
Force/ (Pressure x area)
force
pushes and pulls in a particular direction. measured in newtons (N)
Area
how much space a flat shape takes up. measured in m²
what is weight?
mass x gravitational pull (10)
constant speed
When the speed of an object remains the same
what is a distance-time graph?
A graph with distance travelled plotted on the vertical axis against time taken on the horizontal axis.
what is a journey?
the motion of an object over time
what is gradient?
the rise over the run. (the change in the ‘y’ value divided by the change in the ‘x’ value)
x2 - x1
accelerating
The rate of change of speed increases. acceleration increases.
decelerating
When an object is slowing down.
stationary
when an object is not moving
what is the average speed calculated from a distance/time graph
total distance traveled / total time spent
what does a flat line mean in a distance/time graph?
that the speed of an object is constant (even if its stationary)
what does a curve line mean on a distance/time graph?
the acceleration or deceleration.
