An athlete whose mass is 86.5 kg is performing weight-lifting exercises. Starting from the rest position, he lifts, with constant acceleration, a barbell that weighs 470 N. He lifts the barbell a distance of 0.50 m in a time of 2.0 s. I cannot seem to find the answer to this. This is what i did: - I found the total force exerted on the feet by doing: 86.5*9.8 + 470N = 1317.7N - Then I used d = a*t^2 and got that the acceleration is 25m/s^2 - Then i found the mass of the barbell by doing 470N/9.8 and got 47.96kg. - After using F=ma i added the two forces and got the answer 2516.7N. This isn't the right answer. What did i do wrong? Any help is appreciated. Thanks.