I’m having trouble with my physics lab questions. Can someone help me on these please??

1- In terms of focal length, how far behind the camera lens is the film located when very distant objects are being photographed?

2- Why do older people who do not wear glasses read books farther away from their eyes than do young people? What changes occur w/ respect to the eye’s focal length after many years?

3- What equipment you would need to collect virtual image data using converging (convex) lens? Where should I place the object, and what characteristics of the image would be expected?