Question

An object of height 1.2 M is placed before a concave mirror of focal length 20cm so that a real images formed at a distance of 60 cm from it find the position of an object what will be the height of the image formed?

Answer 1

Height of the object, ho=1.2 m.

Focal length of the concave mirror, f=-20 cm.

Image distance , v=-60cm

Formula:

(1/f)= (1/u)+(1/v)…………….(1)

(1/u)=(1/f)-(1/v)=-(1/20)+(1/60)=-(1/30) OR

u=-30 cm.

For height of the image we use formula

Magnification m= hi/ho=-v/u.( for concave mirror)

Here, ho=1.2m , v=-60cm and u=-30cm.

hi=ho(-60/30)=(1.2)(-2)=-2.4m. The -ve(negative) sign indicates inverted image.

Answer 2

Hey mate ..
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The solution is in the pic .

Hope it helps !!