4. You have an optical system modeled as a thin lens of focal length 10 meter. The object of interest is initially at a distance of 3 km. In the image plane there is a detector array. How far to the right of the lens is the detector array located? (express in meters) If the object of interest moves closer, to a distance of 2 km, by how much does the detector array need to move, and in what direction (toward the lens or away from the lens) to keep the object in focus at its new position? (express in millimeters)

4. You have an optical system modeled as a thin lens of focal length 10 meter. The object of interest is initially at a distance of 3 km. In the image plane there is a detector array. How far to the right of the lens is the detector array located? (express in meters) If the object of interest moves closer, to a distance of 2 km, by how much does the detector array need to move, and in what direction (toward the lens or away from the lens) to keep the object in focus at its new position? (express in millimeters)