I believe its the third answer
If you use the stairs at normal speed, you will survive longer, and go up higher.
When going up the stairs twice as fast, you lose energy more quickly, but height would remain the same.
newtons first law states that a object in motion will stay in motion unless acted on by an outside force and an object at rest will stay at rest for the same reason. the force of a moving object is equal to its mass times its acceleration.
