Patricia Armentrout
48) Protecting money
Author
Series
Language
English
Description
Briefly describes how money and its value are protected by banks, guards, and budgets.
54) The lever
Author
Series
Language
English
Description
Text and pictures introduce the lever, a simple machine used to change force and motion.
55) The pulley
Author
Series
Language
English
Description
Text and pictures introduce the pulley, a simple machine used primarily to lift heavy objects.
56) The screw
Author
Series
Language
English
Description
Text and pictures introduce the screw, a simple machine used primarily as a fastening device.
57) The wedge
Author
Series
Language
English
Description
Text and pictures introduce the wedge, a simple machine placed between objects to split, tighten, or secure a hold.
58) The wheel
Author
Series
Language
English
Description
Text and pictures introduce the wheel, a simple machine used primarily to make it easy to move heavy loads.