A student in your biomechanics class wants to demonstrate to his friends that he can stand perfectly still for 3 minutes with his arms bent in front of him at 90 degrees (the angle of pull of the biceps brachii muscle is 90 degrees). Assuming that the only muscle force acting on the forearm is the biceps brachii, and that it attaches 6.50 cm from the elbow joint, calculate the force required in the biceps tendon to maintain this static equilibrium state.

We assume that the combined length of his forearm and hand is 44.0 cm, and that the student weighs 72.0 kg. We also assume that the elbow is a frictionless joint.

What is the force in the bicep tendon?