Final answer:
The sides of a ladder can be made of wood, metal, plastic, or glass, with the choice depending on the ladder's use and desired properties. Metals are often preferred for their strength and durability, as seen with objects like ladder rungs, as well as in construction materials such as steel.
Step-by-step explanation:
The sides of a ladder can be made from various materials, including wood, metal, plastic, and, though less commonly, glass. The choice of material depends on the ladder's intended use and the desired properties such as strength, durability, weight, and electrical conductivity. In school, when discussing why metal is often chosen for certain objects, students are encouraged to consider these properties. For example, metal objects tend to be strong, durable, and can handle weight and stress well, making metal an ideal choice for ladder rungs.
An additional review about materials can further clarify why metals are often selected for construction purposes. For instance, brass is made of copper and zinc, while bronze is made of copper and tin. Strong and versatile, steel is widely used in construction due to its high tensile strength and durability, and is an example of a substitutional alloy, where different sized atoms replace some metal atoms in the crystalline structure, thus altering the properties.