In a further article on our category Generic Tasks, we want to present you determinations of volume and mass. The focus will be on the bodies Cuboid and Cylinder. Further bodies will follow in future articles. We start with these forms as they occur in the environment very often and can be realised very quickly with our Task Wizard.

Objects that can be described with help of cuboids are for example concrete blocks or stones. Here, the difficulty varies according the unevennesses of the object, which can be balanced through averadged values. With benches, the difficulty can be increased as well, as they have to be described through different cuboids.

Cylinders are very suitbale to determine the volume of a tree trunk. Furthermore, many fountains are circular and therefore a good basis for calcualtions with the cylinder.

 

Especially with stones and tree trunks, the question of the object’s weight seems adequate through a given density. The mathematical background, as well as popular densities can be found in the following document Generic Tasks Volume 1.

As a few weeks ago, the Task of the Week leads us to the African continent, more precisely to the approximately 1000-meter-high Tafelberg in Cape Town. There you can find a monument of stone, which is also an ideal object for a MCM task.


Task: Tafelberg’s Monument (task number: 1791)

Calculate the mass of the stone monument. Give the result in kg. 1 cm³ of granite weighs 2,6 g.


First, the shape of the stone has to be considered more closely. When choosing a suitable model, a prism with a trapezoidal base can be used. For this, it is necessary to ignore minor deviations from the ideal body as well as to operate with the stone mentally. The required data are then determined and the required weight of the stone is obtained by means of the area content formula of a trapezoid, the volume formula of a prism and the given density.

The task shows that over the last few years, MCM has developed into an international platform for authentic “outdoor” mathematic tasks and has already been set up in many prominent places. We are looking forward to further tasks and are looking forward to the countries and regions in which new MCM tasks will emerge.