What part of the body has to cross the finish line first in track?

PARIS, France — The finish to the men's 100 meters at the 2024 Paris Olympics was one of the closest in Summer Games history. 

American Noah Lyles took the title of the "World's Fastest Man" by just .005 seconds and it was determined by a photo finish. On the TV broadcast, it was hard to tell whether Lyles or Jamaica's Kishane Thompson crossed first. 

After some 30 seconds, it was announced Lyles won in 9.784 seconds to edge out the Jamaican by five-thousandths of a second. The breathtaking race had many wondering what were the specific rules surrounding photo finishes and what counts as crossing the finish line at the Olympics. 

What part of the body has to cross the finish line first? 

The Olympic rules state, a runner crosses the finish line when their torso crosses, which is different from their head. That's why some runners lean forward when they cross the line, so their torso crosses first.

Can you dive across the finish line in track?

Yes, it is legal for runners to dive across the finish line, but it's dangerous and not much faster than just running those last few steps. 

For example, in ESPN's Sports Science feature about running or sliding in baseball, they found the jump is faster when the runner first takes off, but acceleration actually decreases while they're in the air.

Who is the World's Fastest Man?

Noah Lyles won Sunday's excruciatingly close sprint to beat Kishane Thompson of Jamaica.

How long is the Olympic track?

An Olympic-sized track is 400 meters around, which is just shy of a quarter of a mile.

How many laps around a track is a mile?

Four  laps across the track is a mile.

How many meters in a mile?

There are 1,610 meters in a mile.

How many miles is 10,000 meters?

A 10,000 meter race is about 6.2 miles.

How many miles is 400 meters?

Four hundred meters, or one lap around a track, equals about a quarter-mile.

TEGNA's Claire Bermudez contributed to this report.