Given:
ho = 7 cm
do = 30 cm
f = 10 cm
Find:
di = ?
hi = ?
Solution:
[tex] \frac{1}{f} = \frac{1}{do} + \frac{1}{di} [/tex]
[tex] \frac{1}{di} = \frac{1}{f} - \frac{1}{do} [/tex]
[tex] \frac{1}{di} = \frac{1}{10 cm} - \frac{1}{30 cm} [/tex]
[tex] \frac{1}{di} = 0.0667[/tex]
[tex]di = \frac{1}{0.0667} [/tex]
di = 1.499 cm
[tex]m = -\frac{di}{do} [/tex]
[tex]m= - \frac{1.499}{30} [/tex]
m = -0.0499
[tex]m= \frac{hi}{ho} [/tex]
hi = m x ho
hi = (-0.0499)(7)
hi = -0.3493 cm