The simplest pure substances that cannot be broken down into any other substances are elements, such as gold (Au) or oxygen (O).
Answer:
Explanation:
Given
mass of archer 
Average force 
extension in arrow 
Work done to stretch the bow with arrow


This work done is converted into kinetic Energy of arrow

where v= velocity of arrow



(b)if arrow is thrown vertically upward then this energy is converted to Potential energy




Answer:
Because winding roads have a gentle slope on hills, so it's easy to climb it than a steepy.
Harder. Not compressible(unless using an extremely strong force). Non-metal have more of a chance of breaking than metals.
Answer:
Person B has four times the power output of person A.