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im in a bit of a panic at the moment

i have 2 days to complete my physics coursework on focal lengths.

the title is:

"you are given two convergin lenses of different lengths. you are to devise an experiment:-

-to measure the focal length of each lense

-to measure the focal length of the lens combination

-to try to find any relationship between the individual focal lengths and the combined focal length."

ive got my readings and some graphs, but there is a little problem. when the graph is plotted, should the line dip back upwards when the image distance gets close to zero? if so why does it do this? if this isnt supposed to happen, and it is because of my crappy reading taking, then i think that i could be up a certain creak, without a certain paddle because i wont have the chance to re-take them...

also, from these graphs how do i calculate the focal lengths? and then the link between the combined and sepourate focal lengths?

any other useful info you think imight need for this assignment would be great too!

thanks a lot for any help!!

cheers,

-Xafron

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# Homework Help: Help with A-level physics coursework. focal lengths of lenses

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