0
What is the focal length of a lens when an object that is 5 meters in front of the lens froms an image that is 2 meters behind the lens?
Wiki User
∙ 13y ago
1/f = 1/i + 1/o
1/f = 1/2 + 1/5 = 7/10
f = 10/7 meters
Wiki User
∙ 13y ago
Add your answer:
Earn +20 pts
How does the focal length of eye changes from a near object to far object?
When you're looking at a near object, the light rays converge at a point behind the retina so the focal length of your eye increases so that the parallel rays of light converge on the back of the retina. Therefore, if you're looking from a near object to a far object, the focal length of your eye should decrease back to its normal, relaxed size.
How can you tell what the focal length is for a lens?
Easy way: Use it to form an image of the sun or moon, and measure the distance of the image behind the lens. When the object is at infinity, the distance between the lens and the image is the focal length of the lens.
How does the focal length of the lens change when you sift looking from a distant object to nearby object?
The focal length of the lens can be changed by the ciliary muscles in the eye due to which we can shift looking from a distant object to nearby object .
What is the relationship between object distance image distance and focal length of a concave mirror?
Sum of reciprocal of object distance and reciprocal of image distance gives the reciprocal of focal length
What will be the power of convex lens having a focal length is 50 cm?
Convert the focal length to meters, then take the reciprocal. That is how the "power" of a lens is calculated.
How does the focal length of eye changes from a near object to far object?
When you're looking at a near object, the light rays converge at a point behind the retina so the focal length of your eye increases so that the parallel rays of light converge on the back of the retina. Therefore, if you're looking from a near object to a far object, the focal length of your eye should decrease back to its normal, relaxed size.
How can you tell what the focal length is for a lens?
Easy way: Use it to form an image of the sun or moon, and measure the distance of the image behind the lens. When the object is at infinity, the distance between the lens and the image is the focal length of the lens.
Focal length of a concave mirror?
1/object distance + 1/ image distance = 1/focal length
What is the focal length of a telescope's mirror if I use an eyepiece with a focal length of 26 mm and I get a magnification of 70x?
1.82 meters
How does the focal length of the lens change when you sift looking from a distant object to nearby object?
The focal length of the lens can be changed by the ciliary muscles in the eye due to which we can shift looking from a distant object to nearby object .
Where does a simple positive lens form an image of a very distant object?
The image is formed behind the lens at a distance equal to the focal length. If the distance to the object is D1 and the focal length is F, then the distance D2 to the image is given by this equation: 1/D2 = 1/F - 1/D1
Do near objects have a longer focal length?
Focal length is related to the lens. It has nothing to do with how near or far the object is to the lens or objective.
What is a focal length?
it is the distance a lense is from an object in order for it to be in focus
What is the relationship between object distance image distance and focal length of concave mirror?
Sum of reciprocal of object distance and reciprocal of image distance gives the reciprocal of focal length
What is the relationship between object distance image distance and focal length of a concave mirror?
Sum of reciprocal of object distance and reciprocal of image distance gives the reciprocal of focal length
What will be the power of convex lens having a focal length is 50 cm?
Convert the focal length to meters, then take the reciprocal. That is how the "power" of a lens is calculated.
What is the limit of the object distance to produce a real image?
Focal Length
