Physical Science Chapter 9: Work and Simple Machines

Vocabulary Words	Objective Questions
9-1  Work and Power	page 258
work power joule	When does a force do work? What is the equation to find work? What are the equations to find power? What is the SI unit of power? What happens to force when it is in two directions or at an angle?
9-2  Using Machines	page 264
input force output force mechanical advantage (MA) efficiency	What does a machine do? How do you find MA? How do you calculate efficiency? Why do you never get 100% efficiency? How can you increase efficiency?
9-3 Simple Machines	page 269
simple machine compound machine inclined plane wedge screw lever wheel and axle pulley fixed pulley movable pulley	What are the six kinds of simple machines? Describe and give a use for each simple machine. What are two machines are really inclined planes? How do you find the MA of a lever? Inclined plane? Wheel and axle? Pulley? Name, draw, label the parts (output force, input force, and fulcrum) and give an example of  the three classes  of levers. Describe how to use each simple machine.

*Science and Society:  Bionic People page 278-279