Answer:
F₀ /k .
Explanation:
Force is variable
F=F₀ [tex]e^{-kx}[/tex]
kinetic energy = work done by force
= ∫ F dx
= ∫F₀ [tex]e^{-kx}[/tex] dx
= F₀ [tex]e^{-kx}[/tex] / -k
E = F₀ [tex]e^{-kx}[/tex] / -k
= -F₀ /(k [tex]e^{kx}[/tex] )
For maximum E , [tex]e^{kx}[/tex] should be minimum ,
[tex]e^{kx}[/tex] is minimum for x = 0
maximum value of E = F₀ /k .