Displacement and velocity of running by Eric Goodney

 One of my favorite things to do in my free time is to exercise, with my favorite activities during the summer months being running and cycling. After completing the first full week of Physics 111, I have become more aware of the physics involved in my activities and have even become surprised regarding certain statistics. Here is a screenshot of a run I did this summer from strava, an app that tracks physical activity. This particular loop took place at the beach in York Maine.

I started my run at my beach house located in the bottom left corner of the strava map. I then ran along Long Sands beach and took a sharp right to head toward Nubble Lighthouse. Once at the tip of the peninsula, I turned around and headed back home.

I am now able to better understand the physics of this activity. I now realize that some statistics of my run are not so impressive. Having learned that displacement is the change in position, my run had a displacement of zero miles since my final and initial positions were the same. Consequently, my run had an average velocity of zero miles per hour due to average velocity being defined as the change in displacement over time.

I have also realized that even if I had ended my run at Nubble Lighthouse, the magnitude of my displacement would be less than the distance I traveled. This makes sense visually, looking at the map, as my distance traveled took place roughly over the shape of two sides of a triangle, whereas my displacement would have been the hypotenuse of that triangle.

I look forward to learning more physics to describe other activities I enjoy, like alpine ski racing. I hope to learn how the force of gravity, friction, and the normal force are involved in skiing down a slope.