Levers

What is a lever

A rigid bar that moves of a fixed point called the fulcrum when a force is applied to it

What is a fulcrum

the pivot point of a lever

What is the effort

applied force (muscle contraction)

What is the load

amount of weight lifted

What are the fulcrums in the body

Joints

What are the levers in the body

Bones

What is the effort in the body

muscle contraction

When does a lever operate at a mechanical disadvantage

When the effort is nearer than load to fulcrum

What is a first class lever

Fulcrum in the middle, effort and load of either side; a seesaw,

What is a first class lever system in the body

Raises the head off the chest

What is a second class lever system

The effort is applied at one end and the fulcrum is at the other. The load is in the middle. A wheelbarrow.

What is an example of a second class lever system in the body

When you stand on your tip toes

What is a third class lever system

The effort is between the load and fulcrum; tweezers

What is an example of a third class lever in the body

Flexing the forearm at the elbow