An optical engineer uses a thin converging lens of focal length f=12.0 cmf = 12.0\text{ cm}f=12.0 cm as a magnifying glass to inspect a microchip, as shown in the ray diagram below.
To produce an upright, virtual image of the microchip that is magnified by a factor of 3.0, at what distance u u\,u from the microchip must the lens be placed?
4.0 cm4.0\text{ cm}4.0 cm
8.0 cm8.0\text{ cm}8.0 cm
16.0 cm16.0\text{ cm}16.0 cm
36.0 cm36.0\text{ cm}36.0 cm