An athlete whose mass is 93.0 is performing weight-lifting exercises. Starting from the rest position, he lifts, with constant acceleration, a barbell that weighs 500 . He lifts the barbell a distance of 0.700 in a time of 2.10 . Use Newton's laws to find the total force that his feet exert on the ground as he lifts the barbell. Take free fall acceleration to be 9.80 . The answer is 1430 N Please show me how to get the answer. I have a physics test on Monday and I need help bad.