Friday, October 21, 2022

Why Does the Road Crack? - Another Question from my Daughters

One of my favorite things to do these days is to ride bikes with my daughters. Sometimes I even record those rides on Strava because my older daughter now wants to keep track of how fast she can go down a little section of road in our neighborhood (current record 10.5mph). When we were riding earlier this week she complained about the cracks in the pavement in one part of our neighborhood and asked, "why does the road crack?" 

I did my best to answer my daughter's question of "why does the road crack?" by explaining that there is a lot of water in the ground in our area. When that water freezes it expands and pushes up on the pavement which then makes it crack. She's six, so I'm not sure she quite got it even when I made the analogy to one of our clay garden pots cracking for the same reason last winter. 

As I almost always do when my daughters ask me a question that I haven't thought about in a long time, I turned to YouTube in search of a visual explanation of why roads crack in the winter. After a little searching I found this video from the Minnesota Department of Transportation. Jump to the 1:14 mark in the video to see an old visual of what happens when wet soil freezes. 



This topic is a great one for an animated explanation. Student can use some simple animation tools to create an explanation of what happens when water and or soil freezes and pushes up against a fixed or rigid object. Register for my new Animated Explanations course to learn how to create and use animated explanations in your classroom.