A retired bank president can easily read the fine print of the financial page when the newspaper is held no closer than arm's length, 59.1 cm from the eye. What should be the focal length of an eyeglass lens that will allow her to read at the more comfortable distance of

Explanation:

comfortable distance is 25 cm .

He must be using convex lens . In that case rays coming from object placed at 25 cm appears to be coming from 59.1 cm due to converging nature of convex lens.

object distance u = -25 cm

image distance v = -59.1 cm

Lens formula

1 / v - 1 /u = 1 /f

-1 / 59.1 + 1 / 25 = 1/f

- .0169 + .04 = 1 / f

.0231 = 1 / f

f = 43.3 m

the answer is kevlar

gas and liquid