The gluteus medius and minimus abduct the hip joint. When you are standing on the right foot, the body tends to till towards the left side. The right gluteus med and min abduct to pull the body towards the right side. This way, our balance is maintained. In this situation, (1) it is the pelvis rather than the thigh that is abducted; (this causes the trunk to flex towards the right); (2) the pivot is the right hip joint; (3) the force is the outward and downward pull of the right gluteal muscles on the pelvis; and (4) the load is the body weight. It is a Class 1 lever mechanism. (An illustration in a general Anatomical Atlas from a popular Germany publisher appears wrong.)
When you are walking, the right gluteus med and min abduct to raise your right foot. In this situation, (1) the pivot is again the right hip joint; (2) the force is the outward and upward pull on the thigh; (3) the load is the weight of the right thigh, leg and foot. The insertion of the muscles are very near the hip joint, whereas the centre of gravity of the lower limb should be farther await from it. It is presumably a Class 3 lever mechanism.
Zigeuner-adjunct, CUHK
A crane is a first class lever when it is winching in or out the rope attached to a load. The crane becomes 3rd class lever when it's boom is luffing, i.e. it is being lowererd or raised.
3rd class lever
Class 1 lever
1st class lever3rd class lever
The Class Lever for Pliers is a class 2 lever.
Class 3 Lever! You Don't even know that!
First class lever
first class lever
class 3
It is a third class lever.
Yes, it is a 3rd Class Lever.
no. a catapult is a class-3-lever not a class-1-lever.