Physics exam 2

focal length concave mirrors

f is positive

focal length convex mirrors

f is negative for convex mirrors

objective difference- do front of the mirror

positive : real image

objective difference - do behinhd the mirror

negative: virtual object

image distance- di in front of of mirror

di is positive - real image

image distance - di behind mirror

negative - virutal image

magnification - positive

positive if image is upright with respect to obj.

magnification - negative

negative if image is inverted with respect to the object

in relative velocity equation u stands for

velocity of object being watched

in relative velociteis equation u’ stands for

velocity of the object as seen by the moving frame

in relative velociteis equation v stands for

velocity of reference frame

Michelson- Morley experiment

goal: find the aether wind by showing light moves at different speeds

result: light actually moved at the same speed regardless of the earths motions

• this tells us that the spped of light is a universal constant

Nearsightedness

this means you can’t see far (myopic)

what lenses are used for nearsightedness

diverging lens

find the the far point correlates to

nearsightedness

• far point is the farthest object can be placed and still seen

farsightedness means

you can’t see close (hyperopia)

what lenses are used for farsightedness

convergin lenses are used for farsightended

the near point correlates to

farsightedness

• This is the closest distance an object can be placed but still seen

propertime (to)

measured by person riding the clock. it is always the shortest time interval that any initial observer can measure for an eventdua

dialated time

measured by anyone watching the clock move. this is the longest time inteval that any initila observer can measure

proper length Lo

length of object measured by someone who is stationary relative to it

• this is th elonger length

contracted length L

length measured by someone moving past object at high speed

• shorter and contracted

sign vonvention lens - focal length for converging lens is

positivefocal length

focal length for diverging lens is

negative

for a lens if an object is on the same side where the light is coming from then

do is positive

• real object

for a lens is the object is on the opposite side where the light is coming from the the

do is negative

• virutal object

in lens if an image is on the opposite side where the light is coming from

• the di is positive

• real image

in a lense if the image is on the same saide where the light is coing from then

• di is negative

• virtual image