a)
Using conservation of energy:
[tex]\begin{gathered} E1=E2 \\ \frac{1}{2}mvi^2+mghi=\frac{1}{2}mvf^2+mghf \\ where: \\ hi=0 \\ vi=14m/s \\ vf=0 \\ so: \\ vi^2+0=0+2ghf \end{gathered}[/tex]Solve for hf:
[tex]\begin{gathered} hf=\frac{vi^2}{2g} \\ hf=\frac{14^2}{2(9.8)} \\ hf=10m \end{gathered}[/tex]b)
[tex]\begin{gathered} W=F_g\cdot d \\ W=9.8\cdot10 \\ W=98J \end{gathered}[/tex]