Physics - terms

Created by

Elsie McRobbie

Cards (39)

all waves require energy
in a transverse wave the oscillation is at 90˚ to the direction of the enrgy transfer
in a longitudinal wave, the oscillation is parallel to the direction of energy transfer
frequency is the number of waves produced each second
radio - communication - aerial
micro - mobile phones - aerial
Infrared - thermal camera - CCD
visible - camera - CCD
UV - anti-counterfeiting - CCD
x-ray - medical - photographic film
gamma - medical - photographic film
refraction is when light changes speed as it moves from one material to another
when light enters a material it bends TOWARDS the normal
when light exits the material it bends AWAY from the normal
diffraction works better for longer wavelengths
model of an atom - proton (+1) neutron (0) electron (-1)
ionisation is when an atom gains or loses electrons and becomes a charged ion
alpha - most - 2 p 2 n - 5cm - paper / skin
beta - medium - fast moving electron - 10m - aluminium
gamma - least - hight frequency light - ∞ - few cm of lead
activity is the number of decays per second
half life is the time is takes the activity of the source to half
weighting factor tells you how ionising the radiation is
Gy is the number of J per Kg
absorbed dose is D = E/m
equivalent dose is H = Dwr
fission - neutron -> uranium -> 2 smaller nuclei -> 3 neutrons + ENERGY
uncontrolled chain - neutron -> uranium -> 2 smaller nuclei -> 3 neutrons (REPEATED)
controlled chain - neutron -> uranium -> 2 smaller nuclei -> neutron (REPEATED)
current is the number of coulombs of charge passing per second
in series, current is the same everywhere
in parallel, current splits across branches
in parallel, voltage is the same across the branches
in series, voltage splits across the components
the current through a resistor is directly porportional to the volatge across it
for combined resistance, answer must be smaller than the samllest resistance, but only just smaller
power describes the number of joules of energy transferred every second
the fuse protects the flex from too high a current
alternating current changes direction, forwards and backwards