The International Olympic Committee has approached you for help in making sprint

Question

The International Olympic Committee has approached you for help in making sprint races fair. In these races, sprinters are started by three commands: “On your marks”, “Get set” and “Blam!” A blank pistol report starts the runners. Winners of these races are often determined by a scant hundredth of a second, or 10 msec, over the course of 100 m. The slightest advantage by a sprinter can mean victory. If a sprinter anticipates the gun, just slightly, he can win the race. In an unfair race, when a runner starts before the gun, the race is stopped by a second blank pistol report. The field is allowed one false start, and the next false start results in the disqualification of the runner who first begins. The IOC wants an automatic determination of when a false start occurs, and their question to you is: what is the minimum reaction time for a sprinter to come off the blocks after hearing the pistol report? How would you determine this reaction time? Knowing what you do about the pathways involved, synaptic delays and propagation velocities, estimate the minimum reaction time.

Hints:

1) the time required for the sound to propagate from the blank pistol to the inner air. Look up the speed of sound in air and human bone, with an estimated total distance.

2) Action potentials are generated in the cochlear and conducted to the brain. AP conduction in the large myelinated axon is 50 meter per second. You may estimate the conduction distance. APs need to be conducted through multiple synapses, with synaptic delay at about 0.7 ms each time. You may estimate how many synapses are there.

3) The brain takes action and move the leg muscles through motor neurons. Again, you need to estimate the conduction of APs from the brain to the legs, including synaptic delays.

Explanation / Answer

The reaction time is the time is takes for the runner to respond to the start signal and begin leaving the starting blocks.there is a limit to how fast a human can react to a start signal. if an athlete left the blocks sooner than 100 m/Sec after the start signal, he was deemed to have false-started.The best athletes reaction times are usually in the range of 120 m/Sec (0.12 sec) to 160 m/Sec . Tim Montgomery improved that to a near perfect 104 m/Sec - and came very very close to being false-started.Most elite sprinters have a spread of 0.02 seconds or more in their reaction times.There are physical limits to how fast an athlete can react to the starters' gun. While the official rules set a limit of 0.100 seconds, it's likely that anyone reacting in less than 0.120 seconds has anticipated the gun.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.