Levers Level 1 Physical Education Pakuranga College 2011

Levers  Levers are simple machines made up of a pivot (fulcrum), effort, and resistance (load) arm.  Levers help apply force.  Longer levers result in greater speed. Good for throwing & striking.  Shorter levers result in greater strength. Good for pulling, pushing and lifting. The most common lever found in the human body is the 3 rd class lever

Components of a lever  Fulcrum – the pivot point around which the movement happens.  Load – The weight that needs to be moved.  Effort – The place where the force is applied. In the body this is the effort produced by the contracting muscles.

Levers in the human body  Levers are made up of the joints (fulcrum), and the bones that connect them to the objects being moved.  Levers in the human body can be manipulated to improve speed, and apply large forces at the same time.

First Class Lever  These levers can help to either increase force or generate more speed depending on the position of the fulcrum.

1 st class example: rowing oar

1 st class body example:

Second Class Lever  These levers allow more force to be produced because the effort arm, is longer than the resistance arm.

2 nd class lever examples: running and press-ups

2 nd class body example:

Third class lever  Third class levers generate speed rather than force

3 rd class examples: hockey stick and baseball bat

3 rd class examples cont.: kayaking and diving board

3 rd class body example

How can we remember these levers? FLE 123 This Statement shows what element is in the middle:  Fulcrum is in the middle in 1 st class levers  Load is in the middle in 2 nd class levers  Effort is in the middle in 3 rd class levers

Practical Lab   Here's what you'll need: a 30 cm plastic ruler 10 objects of varying weights a pencil/pen a level desk or table top

Practical Lab  Create each of the 3 classes of lever using the various pieces of equipment allowed.

1 st, 2 nd, 3 rd class lever examples