Posted by Anonymous on .
An object is dropped off of a 27 meter tall building.
How long is it in the air before it hits the ground?
To measure the height of a tree, a person throws a ball vertically upward, and takes 13 seconds to reach its maximum height which is exactly the height of the tree.
How tall is the tree?

science 
drwls,
One question at a time, please.
The distance a dropped ball falls in time t is
y = (g/2)t^2
In the first question, use that formula to solve for t.
In the second question, I believe your time tom reach the top of the tree should be 1.3 seconds, not 13. Otherwise the tree is unrealistically high. Recheck the problem statement.