Question

An axe cuts only when it is lifted and then struck.

Answer 1

1. An axe when lifted gains potential energy (energy of an object due to its position)
2. While reaching the top most spot axe possess highest potential energy and when it is brought down the potential energy is converted into kinetic energy.
3. With the more kinetic energy, axe is cut into the stem, the higher the speed the more damage or cut faced by the tree.

Thus, an axe cuts only when it is lifted and then struck as it gains potential energy which is transformed into kinetic energy.