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Corkscrew Screw

A screw can work by turning the screw into an object or flat
surface. It is used to lower and raise the things. It is also
used to hold objects together.

Wedge

A wedge is a simple machine made up of Knife
two inclined planes put together. It helps
to cut the things. Axe and knife are Axe

Pulley

A Pulley is a simple machine made up of a wheel and a rope. The rope fits into the
wheel and one end of the rope is attached to the load. It is used to draw water
from the well, and in crane to lift heavy materials.

Pulley Drawing water from well
by the help of pulley
Energy

Energy causes things to happen around us. We need energy to do our work. Energy
exists in various forms like heat energy, chemical energy, light energy, electrical
energy, mechanical energy etc.

1. Heat Energy:
Heat energy is one of the most important forms of energy. The Sun is the main source
of heat energy. Other sources of heat energy are fuels like wood , gas, petroleum etc.
Electricity also produces heat energy.

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