ib physics option c – lenses & mirrors iv mr. jean
TRANSCRIPT
IB Physics
Option C – Lenses & Mirrors IV
Mr. Jean
The plan:
• Video clip of the day
• Refraction & dispersion
• Len & mirror videos
• Examples & Diagrams
• Convex mirror (spherical mirror)
Convex/converging Lens
parallel rays converge to the focal point
fif not parallel, they converge (image formed) at a different point
at each interface, Snell’s law is
satisfied
Where will image be formed?
focusfocus
The equation:
1 1 1
p q f
Ray diagram just like one for concave mirror, except rays continue to right instead of reflecting back!
positive q = right hand side of lens q
Mp
Magnification same:
Concave/diverging Lens
parallel rays seem to be coming from the focal point
f
Diverging lenses
virtual image!The equation:
1 1 1
p q f (negative f)
Negative q: means image on same side of lens as object (virtual)
Thick lenses and surfaces
1 2 2 1n n n n
p q R
1 2
1 1 11n
f R R
Lens-makers’ eqn:
Careful with signs!!! (see table 36.2)
Convex Mirror:
• An object is 15 cm from the surface of a reflective spherical Christmas-tree ornament 6cm in diameter.
• What is the position of the image?