What is the answer to the following problem?You in a race. Yoou need to pick up a basketball, go through a door, climb up a rope, and drop the...

The slowest step in the race is to climb the rope,
everything else is easy.  So you need to find a way to get up the rope quicker or use
something else instead of the rope - perhaps a ladder, a trampoline, or something
similar that would get you to the top more quickly.  Or you could lower the height of
the shelf so you could get to the top of the rope using less
energy.

Now how does this relate to a chemical reaction? 
In many chemical reactions, it is necessary to add some energy to the reaction to get it
started. For example, burning paper.  Paper is a good fuel but you need to first light a
match and put it next to the paper to get the paper started. That small amount of energy
results in a large amount of energy being released when the paper continues to
burn.

Chemical reaction energy diagrams are sometimes used
to illustrate this principle.  Imagine you are on a level surface and have to climb to
the top of a hill.  Once you get to the top  you can then slide down the other side.
Going up you are doing work (using energy) and coming down you are releasing energy.  If
you can make the hill smaller in height you can get to the top soon and then get to
slide down the other side.