Your aunt just turned 50 and now needs glasses to read.

(a) what is the name of this condition? ("–opia")
(b) does your aunt need converging lenses or diverging lenses?
(c) your aunt goes to the store and buys glasses which say +0.75 (meaning, +0.75 d). what is the focal length of these glasses?
(d) assuming these glasses (from part c) bring your aunt’s near point to 25 cm, what is her near point without corrective lenses?

(a) hypermetropia

(b) convex lens

(c) 133.33 cm

(d) - 21.05 cm

Explanation:

(a) As she is old age, so she is suffering from hypermetropia.

(b) It is the defect due to which a person is not able to see the nearby objects clearly, so it is cured by convex lens of suitable focal length.

(c) Power, P = + 0.75 D

Focal length is the reciprocal of power of lens.

f = 1/ P = 1/0.75

f = 133.33 cm

(d) v = -25 cm, f = 133.3 cm

use lens equation

u = - 21.05 cm

a displacement distance is size of displ

the given statement is true.

sensory memory lasts for a fraction of seconds before the information is lost. it is the shortest -term memory and can be called as an element of memory. example: when we look at something and remember what it looks like, is just a second of observation. it degrades very quickly. it can also be considered as the process of perception rather than considering it as a memory.