Comparing the strength of solid wood with that of plywood
The hypothesis that the solid wood will be stronger than the plywood is proven to be true.
Solid wood furniture looks nicer and lasts longer but is more expensive. Another problem with solid wood is that their sizes are limited by the size of the trees. This means more joints are required for larger projects. Plywood on the other hand can be bought at a fraction of the cost of solid wood. It can also be manufactured to larger sizes, making it more convenient to be used in woodworking projects.
What would happen if the science fair project were to be repeated to include oriented strand board (OSB) and fiberboard?
Try repeating the experiment using different widths of wooden planks to compare the results.
Types of wood - http://www.sawdustmaking.com/Wood/wood.html
What is plywood? - http://www.wisegeek.com/what-is-plywood.htm
Ensure that safety equipment (gloves/goggles) are worn when handling power tools. Tools should be handled only by an adult