unit 3 Flashcards
(16 cards)
give all the features of x rays
Part of the electromagnetic spectrum transverse wavelength the size of an atom affect film the same way as light absorbed by bone.
harmful affects of x rays
are ionizing
causes uncontrollable cell growth or cancerous cells
precautions for x rays
Lead shields for protection and film badges
Uses of xrays
scanning and treat cancerous tumours
what is ultra sound?
waves past the human range of hearing. 20000hz
how does ultra sound scanning work?
a transducer produces waves. these hit a boundary between to tissue and then reflect back. this time can be noted and used to make an image.
refrwactive index
how much a material can make light refract
when does total internal reflection happen
when the angle of incidence is higher than the critical angle.
what is the critical angle
the angle of incidence at which t he refracted ray emerges across the boundary
power of a lens measured in
dioptres
iris
opens and closes pupil to allow for a difference in light level
what is centrre of mass
the area of an object where all the mass is thought to be concentrated
what force is use in circular motion
centripetal acting towards the centre of the circle
3 things that affect centripetal force
mass
distance from the centre of the circle
speed
features of an electromagnet
iron core
coils of wire insulated
current passing through
what is used to provide momentum half way through a spin?
a split ring commutator
