(Solved): Most of the motion generated by joints in the human body are examples of levers. An example of a thi ...

Most of the motion generated by joints in the human body are examples of levers. An example of a third class lever is the forearm: the force which generates the motion is located in-between the pivot point and the resistance force. The elbow acts as the pivot point, the biceps muscle pulls up on the forearm to move the mass which is held in the hand. Imagine someone is holding an object in her hand with her forearm horizontal and her upper arm vertical so that her elbow creates a

angle. Her biceps attach to her forearm 0.0597 m from the elbow and make an angle of

with the vertical. A 2.38 kg mass is held in her hand 29.03 cm from her elbow. What force

is exerted by the biceps muscle? Ignore the mass of the forearm.