Learn about the six simple machines (lever, pulley, wheel and axle, inclined plane, wedge and screw) and how they can be used to describe to the human body in motion.
Alignment to NC Essential Standards
- 7.P.2.4 — Explain how simple machines such as inclined planes, pulleys, levers and wheel and axels are used to create mechanical advantage and to increase efficiency.
Students will explain how simple machines, such as inclined planes, pulleys, levers, and wheel and axles, are used to create mechanical advantage and to increase efficiency.
- What are the seven simple machines?
- What is the mechanical advantage for each simple machine?
- What does work mean in science?
- What is efficiency and how is it related to work?
- What is a compound machine?
- Wheel and axle
- Inclined plane
- Mechanical advantage
- Compound machine
Students will work independently to gather information about each simple machine. They will find out how each simple machine increases mechanical advantage and find the equation for mechanical advantage for each simple machine. Then, students will find out what work means in science and how it relates to efficiency. Finally, students will find information about compound machines, which are machines that contain more than one simple machine. The recumbent vehicle that students will see in the extend portion of the lesson contains multiple simple machines.
The websites below are some possible places that students can find information. There are many websites available that students might find during their research. Remind students to check and see if a web page has multiple pages. Some of the websites below are multipage.
- Simple Machines — PBS LearningMedia
- Simple Machines — brainpop.com
- Simple Machines — Neo K-12
- Simple Machines — Idaho Public TV Science Trek
- Calculating Efficiency of Simple Machines — leydenscience.org
- Introduction to Mechanical Advantage — Khan Academy
- Efficiency Formula — Softschools.com
- Physical Science for Middle School — cK-12
After exploring information about the six simple machines, compound machines, mechanical advantage, work and efficiency, students will work in small groups and answer the following questions. If needed, students can review the websites above or other websites to clarify any concepts that they do not understand.
1. What are the six simple machines?
2. How does each simple machine increase mechanical advantage, verbally and mathematically?
3. What does work mean in science?
4. What is efficiency, verbally and mathematically?
5. What is a compound machine?
Each student will work independently for this part of the lesson. Each student will produce a deck of slides. The deck will consist of a slide for each simple machine that describes the simple machine and how it increases mechanical advantage. The description of mechanical advantage should include verbal and mathematical descriptions. The deck of slides should include a slide that describes what work is in terms of science. In addition, students should include a slide that describes efficiency in terms of work. Finally, there should be a slide that defines and illustrates compound machines.
How the slides are completed is up to you and/or the student. Students can create drawings, computer slides, etc.