A thin lens with a focal length of 5.71 cm has a firefly sitting 13.9 cm in fron
ID: 1507775 • Letter: A
Question
A thin lens with a focal length of 5.71 cm has a firefly sitting 13.9 cm in front of it. The height of the firefly is 6.11 mm and 58.5 cm on the other side of lens A is a thin lens B that has a focal length of 28.1 cm and shares a common axis.
Please show a diagram and step by step solving process!
Explanation / Answer
lens equation
1/f = 1/p + 1/q
1/5.71 = 1/13.9 + 1/q
q = 9.69cm
Since the lenses are 58.5 cm apart, this image is the object for the second lens and 58.5 - 9.69= 48.81 cm in front of it
thin lens equation for lens B
1/28.1 = 1/48.81+ 1/q
q = 66.22 cm
overall magnification of two lens is M = ( -q/p )( -q/p)
M= ( -9.69/13.9 )(- 66.22/48.81) = 0.945
The relation between magnification and height is
M = h'/h
h' = Mh
h' = (0.945)(6.11 mm) = 5.774 mm
Since the overall magnification is positive, the image is upright and real
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.