Radius of curvature of second lens surface

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The discussion focuses on calculating the radius of curvature of the second surface of a lens with a power of -5.0D and a convex first surface with a radius of 15.0 cm. The initial calculation yielded a radius of -0.10 cm, but the correct answer is -6.0 cm. A key point raised is the inconsistency in units, as the focal length must be in meters while the radius was given in centimeters. This discrepancy highlights the importance of unit conversion in optical calculations. Properly addressing these unit issues is crucial for accurate results in lens power and curvature problems.
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Homework Statement



A lens of power of -5.0D has a surface which is convex of radius of curvature of 15.0cm. The lens is made of material of refractive index of 1.50.
What's the radius of the other surface of lens?


Homework Equations





The Attempt at a Solution


since power = 1/f
so i have (1/ (-1/5) )= ( (1.5-1)/ 1) x ( (1/15) + (1/r2) )
i found out my r2 = -0.10cm.
But the correct ans given is -6.0cm.
 
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Here, lens of power = -5.0D. (1 Diopter = 1m-1)

And you have taken the P = 1/f, here f is in "meter", but you have taken R1 = 15 cm which is in "cm."

Don't you think this is weird.
 

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