Lever Systems Flashcards

Flashcards covering key vocabulary related to lever systems in the body.

Fulcrum

The support or point on which a lever pivots.

Effort

The force applied to a lever to cause movement.

Load

The weight or resistance that a lever is used to overcome.

First Class Lever

A lever system where the fulcrum is located between the effort and the load.

Second Class Lever

A lever system where the load is located between the fulcrum and the effort.

Third Class Lever

A lever system where the effort is located between the fulcrum and the load. Most levers in the body are 3rd class.

Mechanical Advantage

A measure of the efficiency of a lever system, calculated by dividing the effort arm (distance from effort to fulcrum) by the load arm (distance from load to fulcrum).

Lever Arm

The distance between the fulcrum and the point where the effort is applied.

Torque

A twisting force that tends to cause rotation; equals force times lever arm. (\tau = rF)

In lever systems, what does a longer effort arm provide?

A mechanical advantage, making it easier to move the load.

Give an example of a First Class Lever.

Seesaw, scissors

Give an example of a Second Class Lever.

Wheelbarrow, nutcracker

Give an example of a Third Class Lever.

Tweezers, tongs