In the context of physics mirrors, 'u' and 'v' represent specific distances related to the mirror, object, and image. Here's a breakdown:
Understanding Object and Image Distances
The key concept involves the location of an object relative to a mirror and the resulting location of its image.
Object Distance (u)
- Definition: The distance between the object and the pole (center point) of the mirror is known as the object distance.
- Symbol: It is conventionally represented by the letter 'u'.
Image Distance (v)
- Definition: The distance between the image and the pole of the mirror is called the image distance.
- Symbol: It is conventionally represented by the letter 'v'.
Visual Representation
| Parameter | Symbol | Description |
|---|---|---|
| Object Distance | u | Distance from the object to the mirror's pole. |
| Image Distance | v | Distance from the image to the mirror's pole. |
Practical Insights
- Sign Convention: It's crucial to note that in calculations, a specific sign convention is followed for 'u' and 'v'. Generally, distances measured in the direction of incident light are considered positive, and those measured against the direction of light are considered negative. This sign convention helps determine if the image is real or virtual.
- Real vs. Virtual: A positive 'v' often indicates a real image, which can be projected onto a screen, while a negative 'v' indicates a virtual image, which cannot.
- Mirror Formula: The object distance (u) and image distance (v) are related to the mirror's focal length (f) by the mirror formula:
1/f = 1/u + 1/v.
Examples
- Concave Mirror: If an object is placed beyond the center of curvature of a concave mirror (u is large and negative), then the image might form between the center of curvature and focus on the same side of the mirror (v is negative).
- Convex Mirror: With a convex mirror, if an object is placed at some distance (u is negative), the image will always form behind the mirror (v is positive) and will be virtual.
