Tom’s father is 48 years old. he is not able to see nearby objects clearly. (ref: p.508-511)
a. what may be the reason for his vision problem?
b. where are images formed in this type of defected vision?
c. how is this defect corrected?

a) Hypermetropia

b) Image will form behind the cornea

c) This can be corrected by using convex lens of required focal length

Explanation:

As we know that due to age the iris of the eye lens got weak due to which the  eye lens could not compress of stretch to adjust its focal length to see the far or nearby object

Due to this the focal length of eye could not adjust to see the near objects and it will form the image of nearby object behind the retina of eye

this will form blurred image and it is known as hypermetropia

This defect is corrected by using a convex lens of required focal length and this will adjust the image on the retina of eye

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

false

explanation:

boats, things on boats luggage are way more heavy then water.