Student Activity - It's About Time

INTRODUCTION

From the early 1900s, stopwatches were used to time athletes. Although they were made with metal parts and were a great invention at the time, they would not be suitable for today's Olympic events like the Men's 100m sprint in which competitors power from the start to the finish in less than 10 seconds!

IDEA: You could hold your own running race, using stopwatches to time the runners. Allocate three (3) time-keepers to each runner and compare the three times. Were they different?

As athletes push the limits further, especially in fast events such as the 100m sprint, just a fraction of a second can mean the difference between the gold, silver and bronze medallists.

How is that fraction of a second measured? Modern electronic equipment now enables officials to accurately and confidently declare the winner and the time. This electronic equipment contains the element silicon and many metals including gold, copper, platinum, silver and others.

Judges timing the 100m mens' final Tokyo Olympics 1964 (IOC)

Timing and judging today (Swatch)

In the following activity you will learn about modern electronic timing devices and their importance, using the Olympic Men's 100 metre sprint and Women's 400 metre sprint as examples.

WHAT YOU NEED

Information sheets:

Olympic Men's 100m Sprint Results
Deciding the Winners

 

WHAT TO DO

Task 1

Look at the two information sheets Olympics Men's 100m Sprint Results and Deciding the Winners

• By how much did Hasely Crawford beat Donald Quarrie in the 1976 Games in Montreal, Canada? (Close, wasn't it!) Could a stopwatch have detected that difference? Why not?
• Of the 16 Olympic Games held between 1896 and 1968, in how many Games were the gold and silver medallist, or indeed the silver and bronze medallist, recorded as having exactly the same times?

Cathy Freeman, 1996 Atlanta Olympics (Allsport)

In the 1996 Atlanta Olympics, Cathy Freeman finished second behind Olympic-record breaker Marie-Jose Perec of France in the Women's 400m sprint. Their times were: Perec: 48.35 seconds and Freeman: 48.63 seconds.

• If they had been running in the 1912 Olympics, with a rounded-off time of 48.4 and 48.6 seconds, is it possible that Cathy could have been awarded the gold medal? Explain your reasoning. (Hint: There was up to a 0.2 second difference or "spread" across the 3 stopwatches used, with the middle time of the 3 watches used to award the medals).

To overcome this problem, in the 1972 Olympics the timekeepers began taking times to 1/100^th of a second, instead of only 1/10^th (that is, to two decimal places instead of just one).

• In the eight Games held since then, at which Olympics would the gold, silver or bronze medallist have recorded the same times as each other under the old 1/10^th system? (Hint: you need to round off the times to one decimal place).

Task 2 Now look at the information sheet Deciding the Winners (about the various electronic equipment used in the Olympics) How do you think Welles was able to be declared the winner? What electronic features have been introduced to help increase the accuracy of start and finish times and thus avoid a similar situation?

Alan Welles and Silvio Leonard, 100m sprint 1980 Moscow Olympics Allsport

An electronic memory board is made of the following minerals and metals.

Silicon* gold silver copper platinum

* Silicon can be alloyed with indium, iridium etc to make it a good semi-conductor (ie. conducts electricity one way better than the other).

For any two of the metals used in electronics:

• Where are they mined?
• Where is the nearest of these mines to where you live?
• What properties do they have that make them useful in electronics?
• Write your own interesting or amazing "Did You Know?" about each of them.