Question
i have a question on thin lens equation
how do i know when di is positive or negative?
also i have an example:
A convex lens has a focal length of 60 cm. A candle is placed 50 cm from the lens. What type of image is formed and how far is the image from the lens?
(Is my answer correct?)
G f=60cm
do=50cm
R di=?
A 1/f=1/do+1/di
1/di=1/f-1/do
S 1/di=1/60-1/50
1/di=-1/300
di=-300
P Therefore, the image is virtual and it is -300 cm away from the lens.
how do i know when di is positive or negative?
also i have an example:
A convex lens has a focal length of 60 cm. A candle is placed 50 cm from the lens. What type of image is formed and how far is the image from the lens?
(Is my answer correct?)
G f=60cm
do=50cm
R di=?
A 1/f=1/do+1/di
1/di=1/f-1/do
S 1/di=1/60-1/50
1/di=-1/300
di=-300
P Therefore, the image is virtual and it is -300 cm away from the lens.