Question

відстань від свічки до лінзи 30 см а відстань від лінзи до екрану 20 см . Визначіть фокусну відстань і оптичну силу лінзи​

Answer 1

Ответ:

Объяснение:

дано d=30 см

f=20 cм

F- ?

D- ?

так как изображение на экране то оно действительное

1/F=1/d+1/f=1/30+1/20=(2+3)/60

F=60/5=12 см=0,12 м

D=1/F=8,3 дптр

Answer 2

Calculation of Lens Focal Length and Optical Power

To determine the focal length and optical power of the lens, we can use the lens formula:

1. Focal Length Calculation: - Given: Distance from object to lens (u) = 30 cm, Distance from lens to screen (v) = 20 cm - Using the lens formula: ``` 1/f = 1/v - 1/u ``` - Substituting the given values: ``` 1/f = 1/20 - 1/30 ``` ``` 1/f = (3 - 2) / 60 ``` ``` 1/f = 1/60 ``` ``` f = 60 cm ``` - The focal length of the lens is 60 cm.

2. Optical Power Calculation: - The optical power (P) of a lens is given by the formula: ``` P = 1/f ``` - Substituting the value of focal length: ``` P = 1/60 ``` ``` P = 0.0167 diopters ``` - The optical power of the lens is 0.0167 diopters.

Therefore, the focal length of the lens is 60 cm, and its optical power is 0.0167 diopters.