Response:
45cm
Clarification:
A converging mirror is generally termed a concave mirror. The focal length and the image distance for a concave mirror are both expressed as positive values.
Using the mirror formula to derive the object distance;
Where f denotes the focal length, u indicates the object distance, and v represents the image distance.
Given f = 30cm, and v = 2u (The formed image is double the size of the pencil)
Plugging these values into the formula to solve for u yields;
By cross-multiplying, we obtain;
2u = 90
Dividing both sides by 2;
2u/2 = 90/2
u = 45cm
The object's distance from the mirror measures 45cm