On the planet earth. They exist in what we call the "world", which holds all seen life.
I could be wrong I’m not very smart but I think it’s b
B, because in all truth and honesty, stress is truly inevitable. Also, use process of elimination. I hoped that helped :)
Answer:
h - height
Explanation:
gravitational potential energy = m * g * h
m stands for mass. Mass doesn't change in physics
g stands for gravitational acceleration. It is a constant.
h stands for height. When the skater moves up and down the track the height from the ground changes. Therefore this variable does change.