Question

What distinguishes the three different classes of levers found in the human body?

Answer 1

Answer: C. Levers are mainly grouped as first-class, second-class, or third-class and they are distinguished by the way the joint and muscles attached to the bone are arranged and found in the human body.

Answer 2

Fulcrum and thats the point at which the lever rotates.
Input force also called effort thats the force applied to the lever.
Output also called load thats the force applied by the lever to move the load.