Kuona zviri pedyo uye kuona zviri kure - matambudziko nemhinduro
1. Mwana ane nkuona nzeve anogona kuverenga bhuku ari pedyo nemita imwe chete. Kuti averenge panguva yakajairika mufambo ye 25 cm, sarudza simba re lenzi rinofanira kushandiswa nemwana.
Solution:
Mwana anotambura kuona zviri kure, apo nzvimbo iri pedyo nemaziso ake iri mita imwe kana 100 cm. Nzvimbo iri pedyo nemaziso akajairika i25 cm. Ziso rinogona kugadziriswa kuti rive rakajairwa ne lenzi yakamoneredzwa.
Zvinozivikanwa:
Near point = image distance (s’) = -100 cm
The shadow must be in front of the convex lens so it can be seen. Because the shadow is in front of the convex lens then the image is virtual and signed negative.
Normal reading distance = object distance (s) = 25 cm
Wanted : power of lens
Solution:
The focal length of the convex lens (f) :
1/f = 1/s + 1/s’ = 1/25 – 1/100 = 4/100 – 1/100 = 3/100
f = 100/3 cm
f = (100/3 : 100) m
f = (100/3 x 1/100) m
f = 1/3 m
The power of convex lens (P) :
P = 1 /f = 1 : 1/3 = 1 x 3/1 = 3 Diopters.
Power of convex lens is 3 diopters.
2.
Based on the above figure, determine the eye defect used to normalized the eye.
mhinduro
Eye defects: kuona zviri kure
The light beam can be focused precisely on the retina when a concave lens is placed in front of the eye. Divergent lenses help spread the beam of light so that it can be focused precisely on the retina.
3. Someone can read at the closest distance of 50 cm. In order for him to read at a distance of 30 cm, determine the power of the magirazi emeso lenzi.
Solution:
The person is suffering from pedyo, the lenses used to normalize nearsighted eyes are convex lenses or convergent lenses or positive lenses.
In order for the observed object to be 30 cm in front of the eye, the lens should form an image at a distance of 50 cm in front of the eye. The image is in front of the lens so that the image is upright and virtual.
Zvinozivikanwa:
Object’s distance (s) = 30 cm
Image’s distance (s’) = -50 cm (negative because virtual)
Zvaidiwa: Simba relenzi (P)
Solution:
Focal length :
1/f = 1/s + 1/s'
1/f = 1/30 + 1/-50
1/f = 5/150 – 3/150
1/f = 2/150
f = 150/2 = 75 cm = 0.75 meter = 75/100 meters
Focal length signed positive means the lens used is convex lens.
Power of lens :
P = 1/f
P = 1 : 75/100 = 1 x 100/75
P = 100/75
P = 4/3 Diopters
