A convex mirror of focal length 20 cm forms image of magnification 3/5 for one position of the object. The object is shifted by 16/3 cm towards the mirror. By what distance and what direction the image will move
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Focal length of mirror is-40 cm (‘-’ sign because it is a concave mirror)
Magnification= m = −vu=4−vu=4
−v=4u−v=4u
v=−4uv=−4u
now , by lens makers formula
1u+1v=1f1u+1v=1f
uvu+v=fuvu+v=f
puttingv=−4u,v=−4u,
It becomes,
−4u2−3u=−40−4u2−3u=−40
−4u−3=−40−4u−3=−40
u=−30u=−30
putting u=−30u=−30in v=−4uv=−4u
we get v=120cm
hope it helps
Magnification= m = −vu=4−vu=4
−v=4u−v=4u
v=−4uv=−4u
now , by lens makers formula
1u+1v=1f1u+1v=1f
uvu+v=fuvu+v=f
puttingv=−4u,v=−4u,
It becomes,
−4u2−3u=−40−4u2−3u=−40
−4u−3=−40−4u−3=−40
u=−30u=−30
putting u=−30u=−30in v=−4uv=−4u
we get v=120cm
hope it helps
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