A; A chemical change makes a substance that wasn't there before. Moldy cheese has a new substance, color change and an odor.
Answer:
3 m/s
Explanation:
Kinetic energy of a body is given by the formula
. Let's replace everything we have and solve for what's left.

or 
The appropriate response would be the hollow ball.The purpose for it has more kinetic energy at the last (2/3 as opposed to 2/5) so it will have more potential energy (more height) at the best. Pondering it, more inertia implies its less impervious to change meaning the hollow ball with more inertia wont need to stop as fast.
20 beats per second.
Explanation: 20 x 5 =100