Materials Matter

Students combine paper strips to measure how much gravitational force the paper can withstand by adding masses to the combined paper strips until they tear. Students compare the strength of one paper strip versus the combination of two, three, four, and five strips. Students cut out paper strips and glue them together using a glue stick or a glue bottle. Students punch holes in the paper strips and tie yarn or string through the hole on the paper strip. As they hang the paper strips on the ring stand, they add weights such as a 100 g mass to the paper. When the paper strips tear, the students will record the mass before the paper broke and the mass that caused the tear in the paper. Students will notice that the paper strips tear at increasing masses because of the strength of the combined paper strips.

Students need to understand that composite materials are not created by changing their chemical and physical components. After recording the data, students create a graph with the number of strips on the X-axis and the mass at which the paper tears on the Y-axis. Students compare their findings with the other groups and discuss the results of the project. They discuss why the paper strips could hold more mass as the number of combined paper strips increased. They need to think about what other materials they use in daily life that could be made of composite materials.