Question

o lentila divergenta  are distanta focala egala cu 10 cm .Un obiect  cu inaltimea de 20 cm  se aseaza in fata  lentilei  la distanta de 30 cm .Indicati distanta fata de lentila la care  se va forma imaginea  obiectulului si marimea imaginii.

Answer 1

$\dfrac{1}{f}=\dfrac{1}{x_1}+\dfrac{1}{x_2} \ \ \ \ \ \Rightarrow \ \ \ \ x_2=\dfrac{1}{\dfrac{1}{f}-\dfrac{1}{x_1}}. \\ \\ \\ \\ \dfrac{y_2}{y_1}=\dfrac{x_2}{x_1} \ \ \ \ \ \ \Rightarrow \ \ \ \ \ y_2=\dfrac{x_2y_1}{x_1}$

Datele sunt:
$f=-0.1 \\ y_1=0.2 \\ x_1=-0.3$