How do I keep accelerating in a 100m race? Does holding my breath work, or is it a good start that matters? I'm a 15 year old sprinter.
The rate of change of acceleration is the differential of the acceleration function (the secondary acceleration). This is a fairly subtle concept, but important to understanding how your body distributes its energies efficiently.
I found a paper that covers the concept of optimal pacing in running at the of American Association of Physics Teachers:
which covers (obviously) 400m and 800m, but I imagine the strategies are similar for 100m and 200m.
Note that the world record for 100m is faster for the 150m race where we measure from 50m to the finish. This is because the first 50m allows the athlete to build momentum, and therefore not having to start from 'cold' and not having spent all their energy, they can travel the next 100m quicker.
Usain Bolt ran 100m in 8.72 seconds this way (5.64s at 50m, 14.36s at 150m):