Upon completion of this topic students will be able to:

• distinguish between the different types of simple machines
• describe the advantages of using these machines

Everyone uses some machines every day, some are simple tools, such as bottle opener and screwdrivers; others are complex, such as washing machines, sewing machines, bicycles, and automobiles. Machines, whether powered by engines or people, make tasks easier. A machine does work easily by changing either the magnitude or the direction of a force as it transmits energy to the task. In this unit you will investigate how machines make doing work easier.

Key Terms

• Mechanical advantage
• Velocity ratio
• Work output
• Work input
• Load
• Effort
• Efficency