Lesson 12:

Energy and Machines


Simple machines help us make better use of our muscle power to do work. Simple machines help us lift, pull, or raise items, change the direction of the force, increase the force, split things, fasten things, and cut things. We all use simple machines every day when we open a door, turn on the water faucet, go up stairs, or open a can of paint. Simple machines make work easier. In this lesson, you will learn more about how energy can be transformed to do work using simple machines.


 
 
 

 

In this lesson, you will:

  • look at some simple machines we use to do work
  • consider how the law of conservation applies to machines
  • examine why people want to make machines more efficient



Key terms for this lesson:

  • chemical change
  • compound machine
  • efficiency
  • force
  • friction
  • inclined plane
  • lever
  • mechanical advantage
  • pulley
  • simple machine
  • wedge
  • wheel and axle