question is 29./ about bob and throwing his rock, I have found a./ (225N) easily enough it is b./ which i cannot figure out. Im assuming that it is a newtonian action-reaction pair and that the rock pushes back on bob at 225N as well, which would mean Bob's acceleration would be 3.0ms/s^2. But how do i found his take off speed (I'm asuming kinematics but not sure how with missing variables)?? Answer is 0.2m/s which i cant understand??