Libros de Sally M. Walker (3 libros)

What is matter and where can it be found? Everything in the world is made of matter, whether it is a solid, a liquid, or a gas. Important ideas about matter such as volume, mass, and how matter changes state are conveyed through a series of easy-to-do experiments.

Examines the nature of inclined planes and wedges, how they can reduce the amount of force necessary to perform work, and ways in which they are used.

What causes sound? How does sound travel? Sound begins when matter vibrates. Without this vibration sound could not move and nothing would make any noise. Starting with tiny molecules, this book explains the main concepts of sound and furthers understanding through a series of easy-to-do experiments that will appeal to readers of all ages.