For children in Grade 5 learning about structures and mechanisms. 

From the Curriculum:

In this strand, students will identify and describe forces acting on and within structures. As they measure and compare external forces (natural or human) acting on structures and their effects on different materials, they will develop a more sophisticated understanding of the concept of force and of ways in which structures respond to forces acting upon them. Students will have an opportunity to apply their learning as they design and build structures or mechanisms.

Big Ideas:

• Structures and mechanisms throughout our environment have forces that act on and within them.
• We can measure forces in order to determine how they affect structures and mechanisms. This information can be used to guide the design of new structures and mechanisms.
• Forces that result from natural phenomena have an effect on society and the environment.