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




We have F = kx or ma = kx where m and k are constants. Therefore, if x is halved, a must be halved too.
Answer:443.1 s
Explanation:
Given
Engine of a locomotive exerts a force of 
Mass of train
Final speed (v)
F=ma
so 

and acceleration is


