17.1
17.2
Words to Know
Chapter Quiz
cHaLLEnGe!!!
100
There are ________ different kinds of machines.
Many, several
100
What are three examples of machines that have or act like levers?
seesaws, wheelbarrows, nutcrackers, brooms, bottle openers, scissors, screwdrivers, shovels, and crowbars.
100
A slanted surface used for raising objects to another level is_______.
An inclined plane
100
What two simple machines are types of inclined planes?
wedge and screw
100
True of False? If you have a long enough lever and a strong enough fulcrum you can lift almost anything.
TRUE!
200
All machines are really made from one or more of ___________________.
the six different simple machines.
200
How do inclined planes make the work of going up easier?
They spread the work out over a greater distance
200
What is a wedge?
A simple machine made of two inclined planes.
200
What kinds of machines are most machines?
compound machines
200
True of False? A pulley does not change the direction of the force.
FALSE
300
What is a simple machine?
A machine that changes the size or direction of an applied force.
300
What are a wedge and screw examples of?
Inclined planes.
300
What is a lever?
A simple machine made of a bar or rod that turns on a support.
300
Where is the fulcrum in a Class 1 lever?
Between the effort force and the resistance force.
300
True or False? There is such thing as a Class 4 lever, we just didn't learn about it in this Chapter.
FALSE
400
What are the three ways that machine makes work easier?
Machines change the speed, direction, or amount of a force.
400
Some furniture movers use wooden platforms on wheels. How does this help?
The wheels help reduce friction, the resistance force.
400
What is mechanical advantage?
A measure of how helpful a machine is.
400
What is the force that must be defeated in work?
Resistance force
400
What are some kinds of energy sources that machines need in order to work?
Electricity, moving water or stream, gasoline burning, and a push or pull from a person.
500
What two forces are involved in work?
Effort force and resistance force
500
Give examples of each of the Classes of Levers
Class 1: seesaw Class 2: nutcracker, wheelbarrow Class 3: fishing poles, fly swatters, tweezers
500
What happens when a force moves something through a distance?
work
500
Where would you place the fulcrum of a lever to lift a heavy load most easily?
Close to the load
500
What are the six simple machines?
Lever, pulley, inclined plane, wedge, screw, wheel and axle.
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