Question

A concave mirror forms real image 10cm tall of an object 25cm tall placed at 50cm from the mirror. find focal length and position of image?
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Answer 1

Answer:

v= - 20cm and f=- 14.2cm

Explanation:

height of the object= 25cm

height of the image = - 10 cm( real image)

u = - 50cm

f=?( to find)

v= ? ( to find)

m=-v/u and m= height of image/ height of object

-v/u = height of image / height of object

-v / - 50 = -10/ 25

-v = -10/25× (-50)

v = - 20cm

1/f =1/v + 1/u

1/f = (-1/20) + (-1/50)

1/f = (-50) + (-20) / 1000

1/f = -70/1000

f= - 14.2 cm

Hope it helps u