In this lesson, students learn about work as defined by physical science and see that work is made easier through the use of simple machines. Already encountering simple machines everyday, students will be alerted to their widespread uses in everyday life. This lesson serves as the starting point for the Simple Machines Unit.

Simple machines are devices with few or no moving parts that make work easier. Students are introduced to the six types of simple machines the wedge, wheel and axle, lever, inclined plane, screw, and pulley in the context of the construction of a pyramid, gaining high-level insights into tools that have been used since ancient times and are still in use today. In two hands-on activities, students begin their own pyramid design by performing materials calculations, and evaluating and selecting a construction site. The six simple machines are examined in more depth in subsequent lessons in this unit.

Simple machines are devices with few or no moving parts that make work easier, and which people have used to provide mechanical advantage for thousands of years. Students learn about the wedge, wheel and axle, lever, inclined plane, screw and pulley in the context of the construction of a pyramid, gaining insights into tools that have been used since ancient times and are still important today. Through numerous hands-on activities, students imagine themselves as ancient engineers building a pyramid. Student teams evaluate and select a construction site, design a pyramid, perform materials calculations, test a variety of cutting wedges on different materials, design a small-scale cart/lever transport system to convey building materials, experiment with the angle of inclination and pull force on an inclined plane, see how a pulley can change the direction of force, and learn the differences between fixed, movable and combined pulleys. While learning the steps of the engineering design process, students practice teamwork, creativity and problem solving.

A gear is a simple machine that is very useful to increase the speed or torque of a wheel. In this activity, students learn about the trade-off between speed and torque when designing gear ratios. The activity setup includes a LEGO(TM) MINDSTORMS(TM) NXT pulley system with two independent gear sets and motors that spin two pulleys. Each pulley has weights attached by string. In a teacher demonstration, the effect of adding increasing amounts of weight to the pulley systems with different gear ratios is observed as the system's ability to lift the weights is tested. Then student teams are challenged to design a gear set that will lift a given load as quickly as possible. They test and refine their designs to find the ideal gear ratio, one that provides enough torque to lift the weight while still achieving the fastest speed possible.

This lesson introduces students to three of the six simple machines used by many engineers. These machines include the inclined plane, the wedge and the screw. In general, engineers use the inclined plane to lift heavy loads, the wedge to cut materials apart, and the screw to convert rotational motion into linear movement. Furthermore, the mechanical advantage describes how easily each machine can do work and is determined by its physical dimensions.

Students explore methods employing simple machines likely used in ancient pyramid building, as well as common modern-day material transportation. They learn about the wheel and axle as a means to transport materials from rock quarry to construction site. They also learn about different types and uses of a lever for purposes of transport. In an open-ended design activity, students choose from everyday materials to engineer a small-scale cart and lever system to convey pyramid-building materials.

This lesson introduces students to three of the six simple machines used by many engineers: the lever, the pulley, and the wheel-and-axle. In general, engineers use the lever to magnify the force applied to an object, the pulley to lift heavy loads over a vertical path, and the wheel-and-axle to magnify the torque applied to an object. The mechanical advantage of these machines helps determine their ability to make work easier or make work faster.

In this activity, students gain first-hand experience with the mechanical advantage of pulleys. Students are given the challenge of helping save a whale by moving it from an aquarium back to its natural habitat into the ocean. They set up different pulley systems, compare the theoretical and actual mechanical advantage of each and discuss their recommendations as a class.

Students investigate the ways in which ancient technologies six types of simple machines and combinations are used to construct modern buildings. As they work together to solve a design problem (designing and building a modern structure), they brainstorm ideas, decide on a design, and submit it to a design review before acquiring materials to create it (in this case, a mural depicting it). Emphasis is placed on cooperative, creative teamwork and the steps of the engineering design process.

Students expand upon their understanding of simple machines with an introduction to compound machines. A compound machine a combination of two or more simple machines can affect work more than its individual components. Engineers who design compound machines aim to benefit society by lessening the amount of work that people exert for even common household tasks. This lesson encourages students to critically think about machine inventions and their role in our lives.

Students continue to explore the story of building a pyramid, learning about the simple machine called a pulley. They learn how a pulley can be used to change the direction of applied forces and move/lift extremely heavy objects, and the powerful mechanical advantages of using a multiple-pulley system. Students perform a simple demonstration to see the mechanical advantage of using a pulley, and they identify modern day engineering applications of pulleys. In a hands-on activity, they see how a pulley can change the direction of a force, the difference between fixed and movable pulleys, and the mechanical advantage gained with multiple / combined pulleys. They also learn the many ways engineers use pulleys for everyday purposes.

Students learn about the mechanical advantage offered by pulleys in an interactive and game-like manner. By virtue of the activity's mechatronic presentation, they learn to study a mechanical system not as a static image, but rather as a dynamic system that is under their control. Using a LEGO® MINDSTORMS® robotics platform and common hardware items, students build a mechanized elevator system. The ability to control different parameters (such as motor power, testing load and pulley arrangement) enables the teacher, as well as the students, to emphasize and reinforce particular aspects/effects of mechanical advantage.

Using common materials (spools, string, soap), students learn how a pulley can be used to easily change the direction of a force, making the moving of large objects easier. They see the difference between fixed and movable pulleys, and the mechanical advantage gained with multiple/combined pulleys. They also learn the many ways engineers use pulleys for everyday purposes.

Students learn how simple machines, including wedges, were used in building both ancient pyramids and present-day skyscrapers. In a hands-on activity, students test a variety of wedges on different materials (wax, soap, clay, foam). Students gain an understanding of how simple machines are used in engineering applications to make our lives and work easier.

Simple and compound machines are designed to make work easier. When we encounter a machine that does not fit this understanding, the so-called machine seems absurd. In this lesson, the cartoons of Rube Goldberg are introduced and engage the students in critical thinking about the way his inventions make a simple task even harder to complete. As the final lesson in the simple machines unit, the study of Rube Goldberg machines can help students evaluate the importance and usefulness of the many machines around them.

Through a five-lesson series with five activities, students are introduced to six simple machines inclined plane, wedge, screw, lever, pulley, wheel-and-axle as well as compound machines, which are combinations of two or more simple machines. Once students understand about work (work = force x distance), they become familiar with the machines' mechanical advantages, and see how they make work easier. Through an introduction to compound machines, students begin to think critically about machine inventions and their pervasive roles in our lives. After learning about Rube Goldberg contraptions absurd inventions that complete simple tasks in complicated ways they evaluate the importance and usefulness of the many machines around them. Through the hands-on activities, students draw designs for contraptions that could move a circus elephant into a rail car, create a construction site ramp design by measuring different inclined planes and calculating the ideal vs. actual mechanical advantage of each, compare the theoretical and actual mechanical advantages of different pulley systems conceived to save a whale, build and test grape catapults made with popsicle sticks and rubber bands, and follow the steps of the engineering design process to design and build Rube Goldberg machines.

Students apply the mechanical advantages and problem-solving capabilities of six types of simple machines (wedge, wheel and axle, lever, inclined plane, screw, pulley) as they discuss modern structures in the spirit of the engineers and builders of the great pyramids. While learning the steps of the engineering design process, students practice teamwork, creativity and problem solving.

Students explore building a pyramid, learning about the simple machine called an inclined plane. They also learn about another simple machine, the screw, and how it is used as a lifting or fastening device. During a hands-on activity, students see how the angle of inclination and pull force can make it easier (or harder) to pull an object up an inclined plane.

Students continue their pyramid building journey, acting as engineers to determine the appropriate wedge tool to best extract rock from a quarry and cut into pyramid blocks. Using sample materials (wax, soap, clay, foam) representing rock types that might be found in a quarry, they test a variety of wedges made from different materials and with different degrees of sharpness to determine which is most effective at cutting each type of material.