Force and Motion

Force and Motion	Eyewitness Books
Written by Peter Lafferty	1992
Nonfiction	63 pages
Reading Level ages 8-11

Summary

This is an informational book with many facts about science and different forces and mechanisms that create easier work for us. My favorite page was on pressure and flow. It described how birds were able to get lift by the shape of their wings. Bernoulli was a Swiss mathematician that found the principle of as a flow of liquid or gas increases, it creates lower pressure. Since the bird’s wings are curved, the air above the wing is going faster than the wind moving beneath the wing. This faster moving air forms lower pressure that allows birds to experience lift and flight. Another page was on giant vibrations. It was all about music and how different lengths created different frequencies that translated into different sounds. It described resonance. Resonance is in everything. It is why a class can be exploded. If the resonance created is at the same frequency as the object, it will start to vibrate and eventually cannot hold the oscillations or movement and breaks. This can happen to bridges. In science we learned about the Tacoma Bridge that collapsed because there was a steady wind moving at the same natural frequency as the bridge. This can also happen with ski chair lifts, which is why they shut the lifts down on extremely windy days. Another interesting fact was a pair of Roman scissors. They are created by one metal piece that has fatter, sharp edges on one side and thin middle. It is bent on itself and creates shears. These are a type of lever. The tow cutting pieces revolve around the fulcrum, which is the point of rotation. The effort to use these scissors is less than if it was two separate pieces of metal with the force created by putting them manually together.

Reaction

It was a great book with amazing facts and examples to different types of force and information on the scientists that came up with the theories or laws of force.

Potential Problems

There is a lot of information that may be overwhelming to younger age children.

Recommendations

I would recommend this book to students who enjoy learning interesting facts on how things work and about science that is in everyday life.