The main difference between Lever and Pulley is that the Lever is a one of the six simple machines and Pulley is a simple machine; wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable. A lever is a rigid body capable of rotating on a point on itself.

Second class lever: Second-class levers have the load between the effort and the fulcrum. A wheelbarrow is a second-class lever. The wheel’s axle is the fulcrum, the handles take the effort, and the load is placed between them. The effort always travels a greater distance and is less than the load.

In a third-class lever, the most common in the human body, force is applied between the resistance (weight) and the axis (fulcrum) (figure 1.23a). Picture someone using a shovel to pick up an object. The axis is the end of the handle where the person grips with one hand.

2nd class lever: Gastrocnemius/Soleus – plantarflexion against resistance with the ball of the foot as the fulcrum.

In third-class levers, the fulcrum remains at one end of the beam—however, the force of the effort is now located between the fulcrum and the force of the load. The elbow (fulcrum) and the biceps brachii (effort) work together to move loads held with the hand, with the forearm acting as the beam.

First class levers have the fulcrum between the force and the load. In summary, in a first class lever the effort (force) moves over a large distance to move the load a smaller distance, and the fulcrum is between the effort (force) and the load.

A class 1 lever has the fulcrum between the load and effort. When the load and effort are on opposite sides of the fulcrum, they move in opposite directions. Class 1 levers can be used to make it easier to move an object or make the object move faster, depending on where the load and effort are placed.

Examples of 2nd Class levers: Wheelbarrow; Paper cutter (guillotine); Hinged door; Nutcrackers (two 2nd Class levers.) Tweezers and ice tongs are examples of two 3rd Class levers working together.