3 classes of levers

In class III levers effort is situated between the load and the fulcru..

In class III levers effort is situated between the load and the fulcrum. (shown in the figure below) ..

A simple crowbar can be used to lift a heavy rock with a small effort. The crowbar is an example of a lever. The use of levers was known to the ancient Greeks, and it is reported that Archimedes once remarked "Give me a lever long enough and I will move the world" A ..

Here the power is in the middle and the weight and fulcrum on either side. For example the flexing of the elbow of forearm. Here the elbow joint acts as fulcrum, and the distal part of hand provide resistance. The contracting biceps muscles exert the effort in between fulcrum and resistan..

As a typical example the mechanism in Salvia is described. The flower has a bilipped corolla. There are two stamens and each stamen has two anther lobes which are separated from one another by a long connective. One anther lobe is fertile and the other is sterile. The insect lands on the lower lip..

In this type of lever the effort and the resistance (load) are situated on either side of the fulcru..

In these, the fulcrum is in the centre with weight and power on either side. For example, the joint between the first vertebra (atlas) and occipital bone of skull exhibits first class lever, in which the joint is the fulcrum, contraction of back muscle in the effort and facial ..

In this the weight is in the middle between the power and the fulcrum. For example human body resting on toes. Here the toe forms the fulcrum and contracting calf muscle provides effor..

Levers of the 1 st Order [Class I Levers] - In this type of lever the effort and the resistance (load) are situated on either side of the fulcrum. Let us consider the lever AB which is used to overcome a load L at B by applying the effort E at A. Th..

Levers of the 2 nd Order [Class II Levers] - In these type of levers the load is situated between fulcrum and effort.(shown in the figure belo..