Week 5 - Playground Surfaces

Week 5 - Playground Surfaces

News/Introduction

This week in physics lab, we continued to look into our ways to make a playground safe and exciting. We also looked at another important skill in our look into science, the ENGINEERING DESIGN PROCESS.

 
We can break down each of the different components of this process:
  • Identify the PROBLEM
    • Identifying the challenge, constraints, and finding ways to solve this problem.
  • EXPLORE
    • Completing research on what others have done and experiment with materials for the problem.
  • CREATE
    • Designing and sketching out a plan for your idea. This step also requires justifying your ideas.
  • TRY IT OUT
    • Test the idea and make notes on what worked and what didn't.
  • Make it BETTER
    • Think about how could this design could be improved and make modifications.
For this design challenge, we are looking at playground surfaces. How can we design a playground surface that reduces injuries from falls? For our challenge, we need to prevent an egg from breaking when dropped from a height of 1.0 meters. Additionally, we can only use the materials provided (hay, wood chips, rubber, sand) and our simulated playground surface can not be more than 5 cm thick. 

New Discoveries

My group believed that our surface designs met the criteria for creating a safe and effective playground surface. Our egg dropped successfully from both a height of 1.0 meter and 2.0 meters.
Initial Design (materials from top to bottom - woodchips, rubber, sand)
We even recorded our initial drop!




After initially dropping, we noticed that there was a bounce. From there, we tried to reduce the amount of bounce. We redesigned our playground surface.
Redesigned Surface (added more sand, and mixed the woodchips with the rubber)
We also dropped from the heights of 1.0 and 2.0 meters.

Our 1.0 m drop:


Our 2.0 m drop:

Our model surface could be useful on a real playground. We would probably have to make some modifications to our design. For example, we could remove some of the wood chips to add more sand (as I will explain below). 

In our discussion, we learned that the acceleration equation is vital for an objects impact time. The more the impact time, the less an object decelerates. A sudden stop would break the egg because it has a lower impact time.  During our experiment, we noticed the egg had a bounce when landing on our surface. We determined that we need to reduce this bounce to keep the egg safe. When our egg was falling, it had kinetic energy, but what happens when it hits our surface? The bounce is caused by the energy being transferred to the surface, but the energy being returned to the egg. When there is no bounce (like on sand), the kinetic energy transfers to the sand, and the sand particles carry the kinetic energy away with them. This keeps the egg from breaking.

More importantly, both surface and falling object are affected during the impact. This is a result of a new Newtonian law. Newton's Third Law  states "Objects exert forces on each other that are equal in magnitude and opposite in direction." In layman's terms, Forces come in equal pairs. Each acts on a different object an these forces also act in opposite directions.  For example:


Newton's Third Law can explain this problem. The total weight of the system does not change for a couple of reasons:
  1. There is an upward force from water on the block.
  2. There is a downward force from the block on the water.
These forces balancing each other out means that the weight remains the same. 


Connections

Newton's Second Law boils down to F=ma (Force = mass x acceleration). The higher the acceleration, the higher the force, and vice versa. This relates to our impact time. The higher acceleration means the higher force; therefore, this increases the force. This is why an egg breaks on a harder surface, compared to a softer surface. 

How does what we learned about Newton's Third Law tie in to our overarching question on making a playground fun and safe? We looked at speed and velocity during our "Races" discussion. We looked at Forces and Acceleration while discussing slides. Energy and Forces were the main topics for both swings and playground surfaces. All of these tie together to help us create this ideal playground for children. 

The Future

Because this was our last venture into playground and physics, we discovered various ways to make a playground fun and exciting, but fun. We also built upon what we have been discussing to show that all of these concepts tie together to solve a real world problem. For next week, we will move on to our Space unit! 

Comments

Post a Comment

Popular posts from this blog

Week 1 - Making a Race Exciting

Image
Week 1 - Making a Race Exciting News/Introduction For our first week in our Physics unit, we are thinking about different things that children do while at the park. One such important thing we talked about is how the playground equipment has an important role in the overall design of the park. Some questions we developed as a class were: What makes the playground "fun?" What materials should we use when designing our playground? What other factors do we need to consider when we design a playground (safety, location, etc.)? How can we make this playground "fun?" During our discussion, we explored one thing that is commonly seen on the playground. Children love to race to places or things. As a result, our discussion led to us asking another key question: How can we make a race exciting? But what defines "exciting?" Our class came up with a big idea to make the race exciting. This race has to be close. You want to be on the edge of your seat for the...
Read more

Week 10 - The Rock Cycle

Image
Week 10 - The Rock Cycle The Rock Cycle from:  http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html Introduction Discussing Assessments We started off our lab section by discussing the issue of assessment. When we look at assessment, we have shifted from the standard "learn the material, take a test" to formative and summative assessment. We had to think about how we do assess our students? I believe that formative assessment is the better route to go because this allows for us as teachers to see what our students know. This helps us plan our lessons and also helps us find possible lines of student inquiry. When we also look at assessment, there are inherent dangers in using percentages. What if one student shows growth? Even if that student scores low but shows growth in their progress, is it fair that they still receive a lower score? Across time, grades have skewed higher, this is due to the habit from the Vietnam War era in order to avoid being drafted. Convection ...
Read more

Week 12 - Introduction to Climate Chage

Week 12 - Intro to Climate Change News/Introduction This will be a short intro because we had our geology quiz! But we started off by discussing the documentary  Before the Flood. We learned many things on climate change and how our actions have contributed to the rise in greenhouse gases (methane and carbon dioxide). One contributing factor has to do with the denial of climate change, despite evidence showing.  For our lab investigation, we looked at NASA's Images of Change, and were shocked at some of the images. During this time, we asked about questions that students would ask. But these images were shocking! During this time we also discussed the idea of climate versus weather and came up with an important distinction - weather is a daily measure, while climate is a measure based on the weather for the last 30 years.  The main part of our investigation was looking at the Iowa goldfinch. Is the goldfinch in danger? We looked at weather data at different regions of Iow...
Read more