i`m being asked to find the focal length. I know that the distance from the lens to the object is 35 cm and that the distance from the image to the lens is 27 cm. I did the following:

Question

1/27 + 1/35 = 1/f
62/945=1/f
15 15/62 = f

Did I do this correctly?

Answer 1

your calculations are correct

Answer 2

is my di equal to my focal length?

Answer 3

Like one of my questions asks compare your measured focal length to your calculated focal length. So would my di = my focal length in the experiment?

Answer 4

I don't know the physics behind this, I just assumed your equation was correct.

Your math is correct based on the equation you used.

Answer 5

Thanks so much :)