Question

The water in the beaker acts as a thick lens. There is a mathematical relationship between the thickness of a lens & the place where parallel rays come into focus behind the lens (the focal point of the lens). From your diameter and focal length data table – discuss any pattern in your data that might hint at this relationship for a round lens:

	Distance 1 (diameter of beaker) cm	Distance 2 (distance to focus) cm	Distance 1/Distance 2
Beaker 1	4.5	12.5	0.36
Beaker 2	7.5	8	0.94

Answer 1

given, water in a beaker
diameter of the beaker = d
focal length = f
now for a double sided refraction
from the lens makers formula
1/f = (nw/ng - 1)(4/d)
here nw is water's refractive index and ng is glass' refractive index

hence we can say increasing the diamater of the beaker increases the focal lenght
from the given data we can see
the focal length decreases with increase in the radius of the beaker which is opposirte to what was concluded form the formula