Our science demonstration today was about equilibrium. Students learned that balanced forces aren’t necessarily level in the context of equilibrium. Ask your child what happened when the position of the bottle changed on the coat hanger. Did we achieve static equilibrium after each time the bottle moved? We discussed how equilibrium is an important science concept for engineers to understand.  Students acted out new vocabulary: compression, tension, truss, and cantilever. They can demonstrate each of these terms by acting them out for you at home using the paper they brought home. As we acted out each term, students tried to reach equilibrium.

This afternoon, we learned about the reaction force of bridges. We discussed the direction of the reaction force after a force (such as the weight of a vehicle) pushes on a bridge. Students learned how engineers design bridges so that the abutments react to the weight of the bridge and anything on the bridge. For our bridge-building experiment today, students worked with a partner to create a beam bridge and an arch bridge. They were given two wooden blocks to serve as the abutments. They received two pieces of cardstock for each bridge, Scotch tape, and scissors. They were given constraints and criteria for their bridge. Students designed a bridge and built it together. We used metal nuts to add a force to the bridge to test each bridge’s ability to support weight.

Tomorrow we will make an interdisciplinary connection by learning how engineers use geometry. Students will learn the constraints and criteria for their final project. They will use the engineering design process to brainstorm ideas and sketch a plan. Once the plan is approved, they will be ready to build on Friday!