- #1

Noreturn

- 49

- 0

## Homework Statement

1) A double convex thin lens has a radius of 25 cm for the first surface and a radius of 40 cm for the second surface. If the glass has a refractive index of 1.55 the focal length is a) 28 cm, b) 9.93 cm, c) 121 cm, or d) 63 cm.

2) An object is placed 16 cm in front of a thin concave lens of 10 cm focal length, therefore the image distance

## Homework Equations

1/f=(n-1)((1/R1)-(1/R2))

1/f=(1/s)+(1/s^1)

## The Attempt at a Solution

f=((1.55-1)((1/25)-(1/40)))^-1121cm

s^1=((1/10)-(1/16))^-1

26.67

However, they have the answer as A) 28cm and -6.15

Last edited: