Page 57 - Science Course 2 (Book 2)

5. Machines make work easier by changing the distance the object moves or the force required
to do work on an object.

6. When the input distance of a machine is larger than the output distance, the output force is
larger than the input force.

7. One way to compare how well machines work is to calculate their pulley system.

8. Some work is always transformed into waste energy

Mo9-L2: Key Concept Check

Direction: On the line before each description, write the letter of the term that matches it correctly.
Each term is used only once.

1. expressed as a percentage A. simple machine
B. inclined plane
2. screwdrivers
C. screw
3. bottle openers, scissors, and seesaws D. wedge
E. lever
4. use more than one motion to accomplish tasks F. wheel and axle
G. pulley
5. A single one, such as the kind on a f agpole, changes the direction
of a force. H. complex machine
I. ef ciency
6. pizza cutter

7. Furniture movers often use a ramp to move heavy furniture into
their trucks.

8. changes the direction of the force from one that acts in a straight
line to one that rotates

9. These do not change the amount of work required to do a task; they
only change the way work is done.

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