I believe the answer is the white dwarf.
The sun will cool then heat up again is my understanding. Hope this helps
C. motion can be defined as change in position.
The inner core is solid, while the outer core is liquid.
This question is stated in a complicated way, but all the information we need is right there waiting to be untangled.
We'll start the clock when Todd arrives. At that time:
-- Kate has 5 done. Todd has none yet. Todd is 5 units behind.
From then on:
-- The clock is running. Kate adds 4 an hour to her total. Todd adds 5 an hour.
-- She started out 5 ahead of Todd when he arrived, but Todd does 1 more than Kate every hour.
-- So Kate's 'lead' shrinks by 1 every hour.
-- So <em>Todd will catch up with Kate</em> <em>in 5 hours</em>.
That's the answer to the question ... How long ? It doesn't ask us how many stockings have been filled, but that's easy for us to figure out:
-- Kate had 5 done when the clock started. She fills 4 every hour. After 5 hours, she has (5 x 4) = 20 more filled, and a total of 25 ready to sell.
-- Todd started out with none done. He fills 5 every hour. After 5 hours, he has (5 x 5) = 25 filled and ready to sell. He has caught up with Kate in 5 hours.