Two friends, Joe and Sam, go to the gym together to strength train. They decide to start off with an exercise called flat bench press. Lying flat on a bench with his arms in an extended position, each friend slowly lowers (to his chest) and then raises a barbell back to the starting position. They start off by using a 31.5 kg barbell. Joe is taller than Sam, which means Joe's arms are 70.0 cm long whereas Sam's are 61.0 cm . Calculate the work done by Joe W Joe when he raises the barbell to finish one repetition. The acceleration due to gravity is 9.81 m / s 2 .