Lei's shadow data

Lei checked the length of a shadow each hour today. Here is her data:

 

9am: 39cm

10am: 10cm

11am: 5cm

12pm: 3cm

1pm: 34cm

2pm: 42cm

3pm: 54cm

 

Why was her shadow the shortest at 12pm?

What length do you think the shadow was at 8am?

Lei has a question: 

If you want the shadow to grow longer, do you have to make light source closer to or further away from the object?

Is there another way to make the shadow shorter?