Why the 4x100m relay is faster than the 100m dash
The Sunday Nation
Nairobi,
16 September 2012
Timothy Waituika has observed that World Record in the 4x100m race is 36.84s while that for 100m is about 9.58s. So he asks, “Does it mean that some guys ran faster than [Usain] Bolt?”
If you have missed the reasoning behind Timothy’s question, it is that the four runners in the 4x100m race cover about 100m each thus their average time was 9.21s (36.84 divided by 4). This is 0.42s shorter than the 100m record.
The apparent discrepancy arises because of the way the two races are ran. In the 100m sprint, the runners start from speed zero and then accelerate to maximum. This acceleration eats time.
In the 4x100m race, the first runner accelerates from zero, but the others do not: they begin running when their respective predecessors are about 20 metres away. Thus by the time they take the baton, they are already moving pretty fast.
Therefore, while the average speed during the 100m record-breaking event was 10.38 metres per second (100m divided by 9.58s), Usain Bolt ran much slower at the beginning and much faster towards the end of the race. Remember that he started from zero!
Now 10.38m/s sounds small, so let’s convert it to more familiar units. If one maintained that speed for one hour (60min x 60sec = 3,600s) he would cover a distance of 37,368m (10.38m/s multiplied by 3,600s). That is, 37.368km; therefore the average speed was 37.4km/h.
Data from International Association of Athletics Federations (IAAF) shows that Bolt ran the first 20m in 2.89s. That’s a speed (still an average) of just 6.92m/s (about 25km/h). This is much slower than his race average of 10.38m/s (37.4km/h).
From 20m to 40m, he took 1.75s (speed = 11.43m/s or 41km/h); then 1.67s to get from 40m to 60m (11.98m/s or 43km/h); 1.61s from 60m to 80m (12.42m/s or 44.7km/h); and finally 1.66m from 80m to the finish line (12.05m/s or 43.4km/h).
Thus he reached his top speed somewhere between the 60m and 80m marks. Incidentally, 44.7km/h is very fast, not just for a human being, but also for any animal!
A few days before the 100m final at the London Olympics, the worlds fastest cheetah was recoded doing same distance in 5.95s translating to and average of 60.5km/h. Its top speed during the dash was 98km/h! But let’s not belittle Bolt’s performance: this is an animal built for speed. Humans are built for intelligence and I am sure Bolt would beat the cheetah hands down in a math quiz!
Anyway; the 4x100m record-breaking race, Nesta Carter did the first 100m in 10.28s (9.73m/s). This is significantly slower than Bolt in the 100m event. Michael Frater took the baton from Carter and completed his leg in 9.07s. Next in line was Yohan Blake (9.09s), and finally, the legend Bolt cleared the last 100m in 8.7s!
So the answer to Timothy’s question is both
yes and no: Yes, in the 4x100m race some guys did run faster that Bolt’s
100m event, but no because Bolt was the fastest runner in the 4x100m
team.
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