Question

benda terletak di depan cermin cekung sejauh 30cm dan bayangannya diperbesar 1/2 kali. agar di peroleh bayangan sejati yang sama besar, benda harus digeser sejauh...

Answer 1

awal

perbesaran = M = 1/2

s = 30 cm

s' = M x s = 1/2 x 30 = 15 cm

1/f = 1/s + 1/s' = 1/30 + 1/15 = 1/30 + 2/30 = 3/30 = 1/10

maka f = 10/1 = 10 cm

akhir

perbesaran = sama besar = M = 1......s'=s

1/f = 1/s + 1/s' = 1/s + 1/s

1/f = 2/s

1/10 = 2/s

s = 20 cm

awal benda berjarak 30 cm...akhir benda berjarak 20 cm

MAKA BENDA HARUS DIGESER 10cm MENDEKATI CERMIN