1. The problem statement, all variables and given/known data The above image shows Yelena Isinbayeva (64.1 kg) at a point in her vault where the pole is maximally deflected (Δx = 1.63 m). The pole has a bending stiffness of 1091 N/m and behaves according to Hooke's Law. At this point in the vault, her vertical velocity is 3.25 m/s and she is 2.48 m above the ground. How much work was done be gravity during the time the vaulter went from 2.48 m above the ground to her peak height? 2. Relevant equations P=W/t work done = change in energy Hooke's Law: Fs=kΔx Ws=(1/2)kΔx2 KE=(1/2)mv2 PEg=mgh SE=(1/2)kΔx2 Total energy = KE+PE+SE W=FΔd I have already calculated the following from previous questions Work done on the pole = 1449.34J SE stored in the pole = 1449.34J Force applied to the pole = 1778.33N KE in vertical direction = 338.53J PEg = 1559.48J Peak height of her centre of mass = 5.32m 3. The attempt at a solution I tried: W=FΔd W=(1778.33)(5.32-2.48) W=5050.46 PEg=mgh PEg=(64.1)(9.81)(5.32-2.48) PEg=1785.85 Ws=(1/2)(1090)(5.32)(2.48)2 Ws=4395.75 These answers are all incorrect. I'm not sure how to approach this problem in another way.