Question 1: Muscle Force How can we estimate the force per unit area exerted by human muscles? The obvious way is to find how much you can lift with a particular muscle, and so work out the force it is exerting. And then estimate the cross-sectional area. Human muscles pull with a certain force, but you don't normally lift things directly using a muscle. Instead, the muscle pulls on your bones and causes rotation around joints. Consider a "bicep curl" -lifting something with your arm. Area A Shoulder Bicep musde Force F d Length of forearm L Elbow Joint Your biceps are the muscles in your upper arm. They are not lined up with the bone, but are to one side of it, by some distance d. When these muscles contract, the apply a force F to your forearm bone, a distance d from the elbow joint. This causes the forearm to rotate, allowing you to lift something. Roughly what is this distance d? Select one: Select one: O 2 mm O 2 cm 20 cm 0 2m 0 20 mThe torque provided by this muscle is Tm = Fd. It must be enough to balance the torque (around the elbow joint) caused by a weight. I can lift around 10 kg with my forearm, and my forearm is roughly as long as a ruler-i.e. 30 cm. So how much torque do I need to apply to lift this 10 kg weight? (in newton metres) Answer: Check So based on your answers above, how much force must your bicep muscle apply to lift this weight? Assume the minimum value needed to keep your forearm horizontal. Enter your answer in newtons. Answer: Check my bicep muscles are around roughly 2cm thick and 4cm wide. Using these numbers, and your answers above, what is the approximate force per unit area supplied by my bicep muscles? Select one: Select one: O 103 Nm O 103 Nm 0 10' Nm O 10" Nm O 106 Nm Check