Simple Machines

Simple machines are mechanisms that use leverage (mechanical advantage) to increase the force we apply Simple machines have no moving parts Simple machines are the building blocks that our more complex machines are built upon There are six basic simple machines: lever, wheel and axle, wedge, screw, inclined plane, and pulley

The Great Pyramids Have any of you seen the Great Pyramids in Egypt? What are your thoughts about them? How do you think they were constructed over 5000 years ago?

The Great Pyramids

You have stone, now what? Transportation! Can you imagine how ancient engineers might have transported stone blocks from rock quarry to building site?

Some stones were huge! The Great Pyramid in Egypt has 2.5 million stone blocks Some pyramid blocks weigh as much as 9,000 kilograms (~10 tons) That means one stone could weigh as much as two elephants!

The Great Pyramids Historians estimate that it took nearly 20 years to build some of the great pyramids What do you think were some of the most difficult things people had to do to be able to build them? How strong do you have to be to move a stone weighing 9000 pounds?

The Great Pyramids To build the Egyptian pyramids, engineers had to develop methods of transporting rock a great distance, perhaps hundreds of kilometers Sometimes, they even had to transport rock through flowing rivers Have you ever tried crossing a river or a creek through fast-moving water?

Mesoamerican Pyramids

These were constructed close to 3000 years ago The blocks used to construct the Mesoamerican pyramids were much smaller than for the Great pyramids in Egypt The blocks also did not have to be transported long distances because they used nearby stone Do you think they used the same transportation methods?

Mesoamerican Pyramids It is incredible! While the Egyptian and Mesoamerican cultures existed millennia apart, and we believe there was no formal communication between them, both built incredible structures that have survived to this day. Each stone was cut with such accuracy, delicacy and artistry, that the pyramids are visited in wonder by millions of people each year! In fact, the Great Pyramids in Egypt, are considered to be one of the seven wonders of the world.

LEVER

Lever A lever is a simple machine that provides a mechanical advantage when used. Specifically, it is a bar pivoted on a fixed point (called the fulcrum) that is used to lift an object by applying force to one end.

Lever The idea, usually, is that you apply force to one end of a bar, in order to lift the other end. The easiest example of a lever is a teeter-totter In this case, the fulcrum is between the force and the resistance Can we think of other examples? They are more common than we think

Classes of Levers Effort Resistance Fulcrum First Class Lever

Classes of Levers Effort Resistance Fulcrum Second Class Lever

Effort Resistance Fulcrum Third Class Lever

You Label! R F E Second Class Lever

R F E First Class lever

R E F Third Class Lever

Classes of Levers Examples F E R Third Class Lever

E F R First Class Lever

First Class Lever

Third Class Lever

F E R Second Class Lever

Second Class Lever

Second Class Lever

First Class Lever

Levers It is believed by many historians that ancient engineers used levers extensively to lift or hoist large blocks and stones into place

Wheel and Axle

With the popularity of vehicles today, we can see that the wheel and axle are main components in a very effective mode of transportation. Whether transporting people on long road trips, hauling cement or gravel, or moving furniture, cars, dump trucks, moving trucks and buses are successful modes of transportation.

Wheel and Axle Virtually all methods of transportation use the wheel and axle in some way. Although these types of vehicles did not exist in the early days of pyramid building, the wheel and axle, a simple machine, did exist.

Many archeologists believe that Egyptian engineers transported stone blocks long distances by placing logs under the stones, with large numbers of people manually pulling on a rope attached to the front end of the stone, and continually adding new logs under the leading edge of the stone as the block was rolled forward

Other stone transportation methods included two- to four-wheeled carts. The stone could have been hoisted onto the cart by the same method that is believed to have been used by the Egyptians. However, in the case of Mesoamerican pyramids, where the block size was not as huge, simpler levers could have been used.

Everyday examples Can you think of any items at home or school that use a wheel and axle, or a lever?

Building Stonehenge