Week 5 Blog Post

 This week's big question was "How can we design a safe and durable playground surface?"

Lab

We started off in lab this week going over the reading from last week, "Assessment to Support Student Learning." We each brought up one sentence, one phrase, and one word that stuck out to us from the article.

Then, we talked about the SCAMPER method for engineering design, and how in engineering we are always looking for something that could be improved. With our students in science and engineering, especially those who are more inclined to like science, it's important to always be challenging them to look for something else to improve in their experiment or invention. This way, the focus remains on growth and improvement rather than on getting to a set standard. 

Next, we reviewed the force lens and applied it to the lab activity for the week- the egg drop. My group tried rubber chips on top of sand, and that worked pretty well for keeping the egg safe. We then tried straw and found that that was less effective than the rubber chips. 

As a class, we discussed why certain materials were better as playground surfaces than others. What we talked about was Newton's 3rd law, that every action has an equal and opposite reaction, or Force = Mass x Acceleration. If we want the force to be decreased on the egg, we need the (de)acceleration to be over a longer period of time. Thus, the rubber worked better than plain cement. BUT, if there is too much elastic deformation allowed in a material (such as in the straw or on a trampoline) for the object, energy will be transfered back into it and it will bounce up really high and go in all different directions, eventually causing damage depending on the context. So what we needed to find was a material that allows some elastic deformation, but also allows some of the energy to go into the ground rather than back into the object being dropped.