Question

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 36.0 kg barbell. Joe is taller than Sam, which means Joe's arms are 69.0 cm long whereas Sam's are 59.6 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 .

Answer 1

Work done by Joe

W=243.68joules

Work done by Sam

W=210.48joules

Step-by-step explanation:

The formula for work done is given by

W=Force *distance

W=F*d

Force =mass*acceleration due gravity

F= m*a

Given that

Mass of barbell m=36kg

a=9.81 m/s²

Joe's arm length I.e distance =69cm

To meter =69/100=0.69m

Sam's arm length I.e distance =59.6cm to meter =59.6/100=0.596m

Work Done by Joe

W=F*d(Joe's arm length)

W=m*a*d(Joe's arm length)

W=36*9.81*0.69

W=243.68joules

Work Done by sam

W=F*d(Sam's arm length)

W=m*a*d(Sam's arm length)

W=36*9.81*0.596

W=210.48joules