[poll id=”84″]
ANSWER: A. 210cm
Di = Image distance
Do = Object distance
f = focal distance
1/f = 1/Di + 1/Do
Rearrange to solve for Di: Di = 1/f – 1/Do
1/Di = (1/30) – (1/35)
1/Di = 1/0.0048
Inverse both sides to get Di: ~210cm.
[poll id=”84″]
ANSWER: A. 210cm
Di = Image distance
Do = Object distance
f = focal distance
1/f = 1/Di + 1/Do
Rearrange to solve for Di: Di = 1/f – 1/Do
1/Di = (1/30) – (1/35)
1/Di = 1/0.0048
Inverse both sides to get Di: ~210cm.