posted by aubster .
While sitting on a tree branch 10 above the ground, you drop a chestnut. When the chestnut has fallen 2.8 , you throw a second chestnut straight down.
What initial speed must you give the second chestnut if they are both to reach the ground at the same time?
This is not an answer to your question but I want to point out that no one can answer your question with units. 10 what? 2.8 what? I suggest you repost th question and include ALL of the question instead of part of it.