Work, Force and Energy Notes

TYPES OF SIMPLE MACHINES

•      A tool that makes our work easier by helping us overcome a larger force (load) by applying lesser force (effort) is called a machine.

•      Machines may be simple or complex.

•      A simple machine uses a single applied force (effort) to overcome a single force (load).

Figure 42: Types of simple machines

•      A complex machine consists of two or more simple machines working together.

LEVER

•      A lever is a rigid rod arranged in such a manner that it can move freely around a fixed point.

•      It consists of three parts.

Figure 44: A rod, fulcrum, load and effort make up lever

Fulcrum:

•      This is the fixed point around which the rod moves.

Load:

•      It is the object on which work is to be performed.

Effort:

PULLEY

•      A pulley is a wheel with a groove along its edge, for holding a rope or a chain.

Figure 58: A pulley

•      Pulleys are usually used in sets designed to reduce the amount of force needed to lift a load.

•      A small pulley at the top of a flagpole helps in raising the flag.