A real image of an object formed by a converging lens of focal lenght 15cm is 3 times the size of the object. What is the distance of the object ftom the lens
To solve this problem, 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
- u is the object distance from the lens
Given:
- f = 15 cm
- The image is 3 times the size of the object, which means the magnification (m) is 3.
We know that magnification (m) is given by the formula:
m = -v/u
Rearranging the equation, we get:
v = -m * u
Substituting the given values, we get:
-3 = -v/u
3 = v/u
Plugging this into the lens formula, we get:
1/15 = 1/3 - 1/u
Multiplying through by 15u, we get:
u = 15u/3 - 15
Simplifying, we get:
u = 5u - 15
Rearranging the equation, we get:
4u = 15
Dividing by 4, we get:
u = 15/4
So, the distance of the object from the lens is 15/4 cm.