A photographer uses his camera, whose lens has a 50 mm focal length, to focus on an object 3.5 m away. He then wants to take a picture of an object that is 30 cm away. In which direction must the lens move to focus on this second object? How far must the lens move to focus on this second object?

Aheavy boy and a lightweight girl are balanced on a massless seesaw. the boy moves backward, increasing his distance from the pivot point. what happens to the seesaw? it is impossible to predict without knowing additional information. the side the boy is sitting on will tilt downward. the side the girl is sitting on will tilt downward. nothing; the seesaw will remain balanced.