To become Olympic champions, athletes spend years perfecting every aspect of their performance. The sleek, lightweight uniforms they wear contain the same attention to detail – because at this level, even the slightest advantage can make or break the outcome.
What’s with all the high fashion hairstyles and flashy accessories going on at the Paris Olympics? During the photo finish of the men’s 100m, US runner Noah Lyles was seen wearing a heavy diamond-studded chain around his neck and a large Omega Speedmaster watch.
Lyles won the race 0.005 seconds faster than her rival, but could she have run a faster time without the extra weight? Would sprinter Shakari Richardson have won the gold medal instead of silver in the women’s 100 meters without her long, flowing hair?
Personally, I still think Richardson is the winner on pure glitz and glamour, but do those factors make a difference in finishing time? That’s a question you should ask coach Isaac Newton.
Basic running model
The physics of running are incredibly complex if you dig into the biomechanics, but since our goal is just to estimate the differences, a simple model will suffice.
Immediately after the start, a runner gradually picks up speed. But he doesn’t keep accelerating for the entire distance, even over a short distance like 100 meters. At some point he reaches a constant speed, or slows down a bit. We’ll model a sprinter who accelerates for the first 30 meters, then reaches a constant speed of 11 meters/second (25 mph). If we plot the speed as a function of time, we get this:
Courtesy of Rhett Allan
Let’s look at the acceleration phase of this sprint. When an object accelerates, Net Force It acts on the object in the direction of acceleration. This is Newton’s second law. Fnet = mass x acceleration. So what forces are acting on a running person? Look at the following diagram:
