ch 19 Flashcards
when the object distance is greater than the focal point, what type of image is created for a converging mirror? what is the sign of s’? what is the sign of f?
an inverted, real image on the same side as the object. s’ is positive, f is positive
when the object distance is greater than the focal point, what type of image is created for a converging lens? what is the sign of s’? what is the sign of f?
a real inverted image and s’ is positive on the opposite side of the lens, f is positive.
when the object distance is less than the focal point for a converging lens, what type of image is created? what is the sign of s’, what is the sign of f?
a virtual upright image on the same side of the object, s’ is negative, f is positive
when the object distance is less than the focal point for a converging mirror, what type of image is created? what is the sign of s’, what is the sign of f?
a virtual upright image on the opposite side of the mirror, s’ is negative, f is positive
what type of image is made with a diverging lens? what is the sign of f? what side is the image on? what is the sign of s’
an upright virtual image on the same side of the object, s’ is negative, f is negative
what type of image is made with a diverging mirror? what is the sign of f? what side is the image on? what is the sign of s’
a virtual upright image on the opposite side of the mirror, s’ is negative, f is negative
how does the eye focus
changing its focal length
what does low refractive power mean
it bends the rays at a smaller angle to produce a long focal length
what does high refractive power mean
it bends the rays at a larger angle to produce a shorter focal length
what is total refractive power
it is the sum of the refractive power of two lenses
what type of lens has positive refractive power
converging
what type of lens has negative refractive power
diverging
what is the far point for an eye
it is the furthest point a relaxed eye can see, the focal length is longest at this point and the angle is small
what is the near point for an eye
it is the nearest point a cotnracted eye can see, the focal length is the shortest at this point and the angle is large
what is hyperopia, what is the solution
it is farsightedness, the eye can see far but their near point is further than 25 cm and objects within that range are blurry
the solution is a converging lens that increases the refractive power and decreases the focal length
what is myopia, what is the solution
it is when the far point is not far and distant objects converge too soon in front of the retina
the solution is a diverging lens that decreases the refractive power and increases the focal length
why do objects appear larger than they are
when objects are closer they have a larger angular size
how do magnifiers work
we place an object at the near point of the converging lens and this creates a far virtual image
what does the magnification depend on in a telescope
the eye piece only
what is white light
balanced mixture of colors
what is dispersion and what does it depend on
dispersion is the slight variation of the index of refraction with wavelength
the index of refraction is higher with shorter wavelengths so violet would refract more than red
how do opaque objects appear colored
they absorb light from some wavelengths but reflect light of other wavelengths
what is resolution and aberrations
resolution is the ability to make out fine details, aberrations are lens imperfections
what are spherical aberrations
they are the inability of a spherical lens to focus on a single point
