Thursday, March 26, 2015 – written by STEM Facilitator, Kiara Byrd
The girls had previously learned about floods and now they were going to learn about buildings and more structures. Our guest scientist Christina Sedighi, a civil engineer who works for the US Army Corps of Engineers, really wanted the girls to learn key words to use when it comes to buildings and the materials need to be used. She had the best pre activity for the girls too! The words were tension and compression. First she demonstrated with a piece of string how tension means strong and how compression means weak or loose. By pulling the string from opposite ends, tightened it and made tension. Compression is the opposite and showed by using a marshmallow that when there isn’t any force on the marshmallow, it is loose and easy to pull apart. Now it was the girls turn to be force!! She had the girls stand up and partner up. They were to hold each other’s hands and pull to understand tension and then for them to lean against each other’s backs to understand compression. The girls enjoyed it a lot. After they were being force they had a challenge. Christina had the girls have a competition with each other, in three groups the girls had to build the tallest tower they could in a limited amount of time. The winning group would win a prize. The trick is, they have to build the tower from marshmallows and spaghetti.