Question

I'm trying to figure out what the answer would be to this convex equation, can someone help me please? The convex lens has a focal length of 10.0cm, and the object distance is 15.0cm. The formula is 1/d(o) + 1/d(i) = 1/f. I got 0.06666667, is that correct?

Answer 1

\[\frac{ 1 }{ i }+\frac{ 1 }{ 15 }=\frac{ 1 }{ 10 },\]
\[\frac{ 1 }{ i }=\frac{ 1 }{ 10 }-\frac{ 1 }{ 15 }=\frac{ 2-1 }{ 30 }=\frac{ 1 }{ 30 }\]
distance of image from the lens=30 cm

Answer 2

Thank you! Okay so if I replaced the number "15" with "20" would the answer be 20cm or is that wrong?

Answer 3

that is correct.

Answer 4

Yayy, thank you! I just have one more question. How do you know the characteristics of a convex and concave lens? Also, do concave and convex lenses use the same equations?

Answer 5

I'm filling out this chart on convex and concave lenses. I can do the math part now (thanks to you!) but I still can't figure out how to know if it's small,large, inverted, upright, real, or virtual. This is what my chart looks like. @surjithayer

Answer 6

simple thing for convex lens to remember.
i denote pole =o
focal length =f
distance of object from pole=u
distance of image from pole=v
if the object is
1. at f,image at infinity.
2. between f and 2 f image is away from 2 f.
3. at 2 f ,image at 2 f.
4.away 2f ,image between f and 2 f.
5. at infinity image at f
all these images are inverted and real
remember for a convex lens distance between object and image is \[\ge 4f \]

Answer 7

I'm still confused.

Answer 8

so for the first equation we did would it be smaller, upright, and real? @surjithayer