# Alternative Record Book

## Problem

In the Olympic and Paralympic Games, medals are awarded for the best performances in each event. But what if we used different criteria for writing an alternative record book?

**Investigate some of the questions below to write your own Alternative Record Book.**

*You will need to do some research to answer these questions, and you will need to make some estimations and approximations*. *You may also need to refine the questions to make them more precise. If you can't determine an exact value for certain contexts, you could try to compute upper or lower bounds to allow you to compare.*

In which Olympic or Paralympic event does:

- A human travel fastest? How fast?

- An object travel fastest? How fast?

- An object travel highest? How high?

- A human expend the most calories? How many?

- A human react fastest? How fast?

- A human experience the greatest acceleration or deceleration? How much?

- An object experience the greatest forces, stresses or strains? How much?

**Send us your thoughts about which events should be included in the Alternative Record Book, together with your evidence and calculations.**

Can you think of any other categories to include in your Alternative Record Book?

You may wish to do some experiments and create an Alternative Record Book for your own school and its athletes.

## Getting Started

The 100m sprint isn't the only event where humans move fast! Here are some suggestions of other speedy competitors you could consider:

A cyclist in a sprint

A wheelchair racer in the Paralympics

A diver as he enters the water

A long jumper as he takes off

or perhaps including the Winter Olympics too...

## Student Solutions

Here are some of our ideas about this problem. Do you agree with our answers? Do you have any other ideas?

1. A human travels fastest in the men's 100m race. The record time is 9.58 s and if we subtract an average reaction time 0.15 s then the average speed would be $38.2 km/h$. If we let a human use a bicycle then the event where they travel fastest would be track cycling. The speed is about $70 km/h$.

2. A human reacts fastest again in the men's 100m race. Reaction times are about 0.09 - 0.15 s.

3. An object travels fastest in a shooting event. The speed of a bullet travelling out of a rifle is about $3500 km/h$. Moreover, a ping pong ball can travel about $110 km/h$, a tennis ball travels about $150 km/h$, a javelin travels at $90 km/h$ and in badminton shuttlecocks travel at over $400 km/h$.

4. An object travels highest in a javelin throwing event. A javelin reaches a height of 50m or it could be a missed bullet which can reach a height of a few kilometres.

5. A human's head experiences about 60g acceleration in a boxing event.

6. A human expends the most calories in a cycling - road event. Cyclists are racing for about 7 hours and they approximate burn 9000 kcal.

7. Force. For example a hammer could be thrown for 80 meters. This means it has a speed of about 28 m/s just before being released. The hammer's mass is 7.257 kg and measures 1.215 m. Thus the force on the hammer $(7.257 \times 28^2)/(1.215) = 5 kN$. In a high jump event, the current record is $2.45 m$ which means that the jumper had a speed of $6.9 m/s$. In the high jump, the acceleration off the ground takes about $0.15 - 0.2 s$. Thus, the force a jumper exterts on the ground is $(80 \times 6.9)/0.16 = 3.5 kN$.

Stress is a measure of the average force per unit area. We calculated that the force on a hammer is about 5 kN and we know that the diameter of standard hammer throw wire is 4mm. Thus, the stress in wire is $5000/(1.25 \times 10^{-5}) = 400 MPa$. Moreover, there are high stresses in a pole vault pole about 1 GPa.

Strain is a measure of deformation. It is highest in a pole which is used in a pole vault event. It is about 2.5%. Read more.

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## Teachers' Resources

### Why do this problem?

This problem invites students to take a look at the amazing limits that athletes push themselves and their equipment to in search of Olympic glory.

In order to come up with answers, students will need to undertake some research, calculate with measurements and different units, and make comparisons.

### Possible approach

**For younger students**, concentrate on the first few questions dealing with speed, distance and time. **Older students** studying mechanics and physics may be interested to explore questions on acceleration, stresses and strains.

"What Olympic records do you know about? Do you know who holds the record, and what it is?" *Students will share their knowledge of Olympic events and records.*

"What if we wanted to make an Alternative Olympic or Paralympic Record Book? For example, we might want a record for the event where a human travels the fastest. Talk to your partner and suggest which event might hold this record."

Give students a couple of minutes to discuss, and then collect their suggestions on the board. If everyone suggests that it must be e.g. Usain Bolt running the 100m, invite them to consider some other possibilities:

- A cyclist in a sprint
- A wheelchair racer in the Paralympics
- A diver as he enters the water
- A long jumper as he takes off
- or perhaps including the Winter Olympics too...

If students reject cycling/wheelchair as they include extra equipment, suggest that they might have two categories in their record book, for fastest unaided human and for fastest aided human.

"You'll need to do some research to determine for sure which one of these would get the record."

Perhaps invite students to suggest some other categories for their record books, or offer them the ones from the problem. Then allow them time for research in groups, either to research one question of their choice or a range of questions.

Finally, each group can produce their own 'Alternative Record Book' or if each group has worked on one question, their work could be compiled into a class Record Book.

### Key questions

Which events are likely candidates?

Have you taken a look at the list of Olympic events to check that you haven't missed any out?

What research and calculations will you need to carry out in order to compare the speeds and distances in different events?

### Possible extension

The later questions on forces, stress, strain and acceleration require the use of more advanced mathematics, and may prompt students to think of their own challenging follow-up questions.

### Possible support

To get students thinking about measurements and units at the Olympics, start with Olympic Measures.