- #1
PhysicsGirl90
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Homework Statement
With a lens with f = 25 cm, we want to project an image that is 5 times bigger than object, so M = 5
- Find the image distance s'
- Find the image height Hi
Homework Equations
1/f = 1/s + 1/s'
M = s'/s = Hi/Ho
With:
f = focus distance of lens
M = magnification
s' = image distance
s = object distance
Hi = image height
Ho = object height
The Attempt at a Solution
From the second equation we get: 1/s = M/s'
Substitute that in first equation to get s':
1/f = M/s' + 1/s' --> s' = (M+1)f = (5+1)*25 = 150 cm
The problem is now i don't know how to get the image height...from our answer we can easily calculate that s = 30 cm, so we know:
M = 5
f = 25 cm
s = 30 cm
s' = 150 cm
how do i get Hi?