posted by daniel .
hey, i was wondering if someone could explain and help me with this problems.
please and thank you!
A person holds an object of mass m = 4 kg on the palm of the hand with the arm stretched as shown in the attached figure. Use the torque equilibrium equation to determine the magnitude of the force F exerted by the biceps muscle when a = 27 cm, b = (0.15 · a), and the angle θ = 75°. Neglect the weight of the lower arm.
A person bends over as shown in the attached figure, part (a), and lifts an object of mass m = 29.2 kg while keeping the back parallel with the floor. The muscle that attaches 2/3 of the way up the spine maintains the position of the back. This muscle is called the back muscle or latissimus dorsi muscle. The angle between the spine and the force T in this muscle is θ = 10°.
I can't offer any help without a diagram.