1. The problem statement, all variables and given/known data Bob, who has a mass of 85 kg, can throw a 450g rock with a speed of 30m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.8m. a.) What constant force must Bob exert on the rock to throw it with this speed? b.) If Bob is standing on frictionless ice, what is his recoil speed after releasing the rock? 2. Relevant equations F=ma 3. The attempt at a solution I have no idea how to start this problem. There are way too many elements of the problem for me to know how to start.