Wednesday, October 31, 2018

When I was looking up Balsa wood I came across a Wikipedia entry of Ochroma pyramidale which is a type of plant that is more commonly known as a balsa tree. This tree grows relatively fast up to 100 feet talk and is very lightweight. It grows natively in Brazil and some places in Bolivia and southern Mexico. Based on its speed of growth it can often reach almost its full height in ten to fifteen years which is why the material is often so light and it is even lighter and less dense than cork. These trees have a relatively short life span of about thirty to forty years. Due to the soft and lightness of this material it is quite popular for building models. It has a coarse and open grain wood structure. The wood can be somewhat spongy and a lot of air in the wood. Often the wood is used to test model airplanes and buildings and bridges. They can be used in some fishing applications and creating pens. They may be used in wind turbines or in wood composites such as for ping pong and also for stage props when something needs to be broken on stage. The wood can also be used in some surfboards or for simple whittling of which it is extremely popular.

One of our first favorite projects was using a few sticks of it to test downward torque and shear pressure on a bridge model to see how many Newtons or psi units of pressure would be sufficient to destroy a bridge and compare that against something like an egg shell.

This material is a great tool for teaching kids and adults alike about density and mass.