mock test Flashcards
distance
not a vector quantity
magnitude of velocity
area under accelerTION TIME GRAPH
LDR and NTC highest resistance combo
light and cold
why might a reading show the emf
because of internal resistance volts are lost
internal resistance equation
V = E -Ir
why is digital equipment better
more accurate and easier to read as it gives a direct value/reading and you don’t have to read off of a scale
why might assumptions not be accurate in real life
acceleration isnt likely to be uniform. as speed increases air resistance increases so the acceleration is not contant. also the amount he brake is not likely to be contant.
cos 25 = 50/ x
correct
why does resistance vary
as voltage increases the energy of the electrons increase therefore there are more collisions and more energy is transferred. This energy causes temperature to increase and therefore resistance increases and results in a rate of change of current with respect to potential difference.
hookes law
extension is directly proportional to force
elastic potential energy equation
E = 1/2fx
why is velocity often lower than expected
work has to be done against friction
photon model for radiation vs wave model
The energy of one photon is used to liberate one electron meaning the threshold frequency must be high enough, using the wave model the frequency would build up to high enough to liberate and electron.
The energy is proportional to the frequency and any energy greater than the work function is transferred t the electron as kinetic energy, using the wave model K.E. would depend on intensity instead
if the frequency is greater than the threshold frequency an electron is emitted instantaneously as there is enough energy.
why does intensity decrease over distance
the area the wave is spread out over is larger so the intensity is lower (interference can also effect the intensity)
unit of viscosity
PaS
