1. An athlete whose mass is 90.0 kg is performing weight-lifting exercises. Starting from the rest position he lifts, with constant acceleration, a barbell that weighs 490 N. He lifts the barbell a distance of 0.60 min 1.6 s. a) Draw a clearly labeled freebody diagram for the barbell and for the athlete. b) Use the diagrams in part a) and Newton's laws to nd the total force that his feet exert on the ground as he lifts the barbell. (C) (D) fB on A = fA on B This can't be determined here