Answer:
a) p = 95.66 cm, b) p = 93.13 cm
Step-by-step explanation:
For this problem we use the constructor equation
where f is the focal length, p and q are the distances to the object and the image, respectively
the power of the lens is
P = 1 / f
f = 1 / P
f = 1 / 2.25
f = 0.4444 m
the distance to the object is
the distance to the image is
q = 85 -2
q = 83 cm
we must have all the magnitudes in the same units
f = 0.4444 m = 44.44 cm
we calculate
1 / p = 0.010454
p = 95.66 cm
b) if they were contact lenses
q = 85 cm
1 / p = 0.107375
p = 93.13 cm