Machine

Simple machine are those tools or devices which make our work easier and convenient  in the direction of the force. They are of six types:

                      1. Lever                                        2. Pulley

                      3. Inclined plane                           4. Wheel and axle

                      5. Screw                                        6. Wedge

Simple machines make our work easier in following ways:
1.          By multiplying force.
2.          By changing the direction of force.
3.          By transferring force from one point to other.
4.          By increasing the rate of doing work.