1. The problem statement, all variables and given/known data A 0.16 kg pinecone falls 18 m to the ground where it lands with a speed of 11 m/s. a)How much work was done on the pinecone by air resistance? b)What was the average for of air resistance exerted on the pine cone? 2. Relevant equations ƩF=ma Vf^2=Vi^2 + 2aΔx W=FΔx=maΔx=1/2(mVf^2)-1/2(mVi^2) 3. The attempt at a solution I tried using the kinematic equation to find initial velocity while setting the acceleration as gravity. I got 18.78 m/s but that doesn't seem right. I tried using that initial velocity in the work-kinetic energy theorem and it came out to -28.275. However that was the wrong answer. I don't understand where to start with this problem let alone part B. Someone help me please.