Simple Machines

I use hundreds of different machines to help us with my work. Machines help us travel, farm the land, make things for us, type my letters, wash my clothes. Machines put forces to work. They help us to do things more easily and usually quickly. t is much faster to sew a dress with a sewing machine than it is by hand. Most machines are driven by engines or electric motors.



Some machines are very simple indeed. I use a hammer as a machine when i take out a nail with the prongs on its head, because me are using the hammer as a lever, which is one of the simplest machines. I often use levers to apply extra force to something. Garden spades, tweezers, and pliers are all kinds of lever. I use them as machines to help me do something more easily.


The screw and wedge are other simple machines. I can easily turn the screw of a workshop vice to make it grip something tightly. An axe has a head shaped like a wedge. The wedge has a thin edge to go into the wood easily, and then the sides of the wedge force the wood outwards so it splits.

Other simple machines use wheels. A pulley is a wheel with a rope running over it. By fastening loads to pulleys, i can make it easier to lift heavy things. I just have to pull on the other end of the rope. Another wheel machine is the wheel and axle, which is like a pedals and chain wheel on a bicycle.

I can make my bicycle go on pushing the pedals. A chain carries the force of my pedalling to the axle of the back wheel, and turns it round. The chain joins a gear wheel on the pedals to a smaller one on the back wheel. This smaller wheel turns faster than the pedal gear, and that makes my pedalling turn the bicycle wheel faster.