Why does the sun rise later the day after the winter solstice than on the day of the solstice itself?

I am going to defer to the experts for this one. The US Naval Observatory
has a division that computes the rise and set times for the Sun.
If you go to their Frequently Asked Questions page

http://aa.usno.navy.mil/AA/

and click on The Dark Days of Winter, you will find the answer
to your question. I'm not sure how digestable by fourth graders
it will be, unfortunately. They also have an Need Help? email
address, so maybe they can more helpful in this regard as well.
Good luck!
Jennifer Johnson

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