Question

How far should an object be from a concave mirror of radius 0.36m to form a real image 1/9th of its size?(hint: u=?,R=-0.36m ,f=-0.18)

Answer 1

Answer:

u = 1.44 m

Explanation:

f = .18 m

-v /u = 1 /9

- 9v = u

1 /v + 1 /u = 1 /f

1 /v - 1/9v = 1 /.18

8v /9$v^{2}$ = 1 /.18

8 /9v = 1 /.18

v = 0.16 m

u = 9 x 0.16 = 1.44 m

Answer 2

Answer:

u = 1.44 m

Explanation:

f = .18 m

-v /u = 1 /9

- 9v = u

1 /v + 1 /u = 1 /f

1 /v - 1/9v = 1 /.18

8v /9v^{2}v

2

= 1 /.18

8 /9v = 1 /.18

v = 0.16 m

u = 9 x 0.16 = 1.44 m