Physics - Please help

[Shaley]

For real images in converging lenses, I know that if the object distance increases, then the image distance will decrease. However, I need to explain WHY and I don't know? Pleaes help

 

[rl.bhat]

For a given converging lens focal length is constant. The formula for lens is
1/f = 1/u + 1/v,
As u increases, v decreases to keep 1/f constant.

 

[kerimek]

The reason why the image distance decreases when the object distance increases in converging lenses is due to the relationship between the object distance, image distance, and focal length. In converging lenses, the focal length is always positive. This means that the light rays passing through the lens will converge at a point known as the focal point, located on the other side of the lens from the object.

When the object distance increases, the light rays entering the lens will be less divergent, meaning they will be closer to parallel. This results in the light rays converging at a point closer to the lens, thus decreasing the image distance. In contrast, when the object distance decreases, the light rays will be more divergent, causing them to converge at a point further away from the lens, increasing the image distance.

This can also be explained using the thin lens equation, which states that the product of the object distance and image distance is equal to the focal length of the lens. As the object distance increases, the image distance must decrease in order to maintain this relationship.

In summary, the decrease in image distance as the object distance increases in converging lenses is a result of the light rays being less divergent and converging at a point closer to the lens, and is also supported by the thin lens equation.