Answer to Question #19770 in Mechanics | Relativity for Kelly

Question

A body builder at the gym is lifting a 40kg dumbell. His arm measures 0.2m from hand to elbow and 0.4m from elbow to shoulder.
1) If he does a front shoulder raise so that his shoulder is in the center of the circle, how much torque will it require?
2) If he can exert a torque of 610Nm while doing a front shoulder raise, what is the largest dumbell he can lift?
4) If he can exert a torque of 353.8Nm while doing a biceps curl, what is the largest dumbell he can lift?