Question

Формула есть не умею считать обыкновенные дроби! изображение предмета находится на расстоянии 40 см от рассеивающей линзы с оптической силой 2 дптр На каком расстоянии от линзы находится предмет

Answer 1

 дано:
f=40 см =0,4м
D=2 дптр
d-?
1/d-1/f=-1/F
F=1/D=1/2=0,5м
1/d-1/0,4=-1/2
1/d-2,5=-0,5
1/d=-0,5+2,5
1/f=2
f=0,5
Ответ   50 см

Answer 2

Calculation of the Object Distance from the Lens

To calculate the distance at which the object is located from the lens, we can use the lens formula:

1/f = 1/v - 1/u

Where: - f is the focal length of the lens - v is the image distance from the lens (positive for real images, negative for virtual images) - u is the object distance from the lens (positive for objects on the same side as the incident light, negative for objects on the opposite side)

In this case, we are given that the image is located at a distance of 40 cm from the lens. The optical power of the lens is given as 2 diopters (D).

To find the object distance, we need to rearrange the lens formula:

1/u = 1/f - 1/v

Let's substitute the given values into the formula and calculate the object distance.

Given: - Image distance (v) = 40 cm - Optical power (P) = 2 D

To find the focal length (f), we can use the formula:

f = 1/P

Substituting the value of P into the formula:

f = 1/2 = 0.5 m = 50 cm

Now, let's substitute the values of f and v into the rearranged lens formula to find the object distance (u):

1/u = 1/50 - 1/40

Simplifying the equation:

1/u = (40 - 50)/(40 * 50) = -1/200

Taking the reciprocal of both sides:

u = -200 cm

Therefore, the object is located at a distance of -200 cm from the lens. The negative sign indicates that the object is on the opposite side of the lens from the incident light.

Please note that the negative sign indicates the position of the object relative to the lens and does not have a physical meaning in this context.