Keeping Up
Difficulty | |
Time Required | Very Short (≤ 1 day) |
Prerequisites | None |
Material Availability | Readily available |
Cost | Very Low (under $20) |
Safety | Requires adult supervision when seeking volunteers |
Abstract
Do you ever feel like you need to walk faster than your parents just to keep up with them? This is because of the difference in leg length between you and your parents. How much faster do you need to walk than your parents? Can you use a walking test to determine how tall a person is?Objective
Test if the height of a person is related to their walking pace, and if this information can be used to estimate the height of a person.
Credits
Sara Agee, Ph.D., Science Buddies
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I Did This Project! Please log in and let us know how things went.Last edit date: 2013-11-25
Introduction
A pedometer is an instrument that is often used by joggers or walkers to tell them how far a distance they have gone. The name pedometer comes from the latin words "ped" which means to walk, and "meter" which means to measure. On some pedometers when a person sets the instrument before an outing, they must enter their height, or how tall they are, into the pedometer to get an accurate reading. Figure 1, below, shows a picture of a pedometer.
Figure 1. Here is a picture of a pedometer designed just for kids to be easy to use and accurate for small steppers. (product by Silva, Sweden) |
Why is height an important variable for measuring how far a person has walked? One part of the answer has to do with ratios, which are fractions that are used to describe the relationship between two measurements. Our bodies have many interesting ratios in them. For example, when your arms are outstretched the distance from the tip of one hand to the other is usually equal to your height. This type of ratio is called a one-to-one (written 1:1) ratio. There are other types of ratios as well, each describing how one part of the body relates to another in size. Because the length of a person's legs is related to a person's height by a ratio, the height of a person will effect how long of a step they take. The longer each step is that you take, the more distance you will travel when walking, jogging or running. This ratio, combined with the motions involved in walking, are how pedometers measure distances.
The measurements of a pedometer are based on the hypothesis that all people have common ratios and proportions, even if they are different heights. In this science project, you will test this hypothesis by measuring the height of different individuals to see if this is related to the number of steps they take to walk a certain distance. Thinking about walking and looking at the picture of people walking in Figure 2, below, do you think the result be a ratio? Will the ratio of different volunteers be the same? Can you use the ratio to predict the height of a person by counting the number of steps they take to walk a certain distance?
Figure 2. Do you think a person's height is related to the number of steps they take to walk a certain distance? Try this science project to find out! |
Terms and Concepts
- Pedometer
- Distance
- Height
- Ratios
- Best fit
- Estimate
Bibliography
- Peaceful Playgrounds. (n.d.). Pedometers for Kids Track Physical Activity. Retrieved October 23, 2013, from http://www.peacefulplaygrounds.com/pedometers-track-physical-activity/
- Moldofsky, K. (2013, Sept. 26). Simple Ratios of the Human Body. Bedtime Math. Retrieved October 23, 2013, from http://bedtimemath.org/ratios-of-the-human-body/
- Klein, Aaron. 1977. You and Your Body: A Book of Experiments to Perform on Yourself. Garden City, New York: Doubleday and Company, Inc.
For help creating graphs, try this website:
- National Center for Education Statistics, (n.d.). Create a Graph. Retrieved June 2, 2009, from http://nces.ed.gov/nceskids/createagraph/
Materials and Equipment
- Pen or pencil
- A park with a jogging path or similar location where you can ask for volunteers as they pass by. You will need at least 10 volunteers.
- Sidewalk chalk
- Tape measure, metric
- Optional: Graph paper
- Straight edge ruler
- Lab notebook
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I Did This Project! Please log in and let us know how things went.Experimental Procedure
- In your lab notebook, make yourself a data table like Table 1, below, to bring with you when you do your experiment.
- You will be writing down each volunteer's height and the number of steps they took when walking a certain distance.
- You should do this experiment with at least 10 different volunteers, so make sure there is enough space in your data table to write down all of your data.
Height (cm) | Number of Steps Taken | |
Volunteer 1 | ||
Volunteer 2 | ||
Volunteer 3 | ||
... | ||
Volunteer 10 |
- Find a place for your experiment. The ideal place would be a park with a jogging path where you can ask for volunteers as they pass by.
- Be sure to have a parent come with you and supervise while you seek and talk to volunteers. Also have your parents' permission to speak with strangers.
- Measure out your distance for the walking test. Using your tape measure, measure out a distance of 6 meters (m) and mark the beginning and ending points with a piece of sidewalk chalk.
- Find a volunteer and do the following:
- Measure the height of the volunteer with your measuring tape in centimeters (cm). Write down the height of the volunteer in your data table.
- Ask the volunteer to walk from the beginning to the end of the 6 meter course you marked, while counting the number of steps they take. Write down the number of steps in your data table.
- Politely thank the volunteer for helping you with your experiment.
- Repeat step 4 for at least 9 more volunteers so that you have tested a total of at least ten volunteers. Try to find at least ten volunteers of different heights.
- After collecting your data, you will need to make a graph. You can make the graph by hand or use a computer program like
Create a Graph to make an XY scatter graph and print it out.
- Plot the number of steps on the bottom axis (X-axis) and the height (in cm) on the left axis (Y-axis).
- For each volunteer, make a dot where the height and the number of steps cross.
- When you are done plotting your points, you should have one dot for each volunteer.
- Look at your dots and see if they almost make a straight line. Use a ruler to draw a "line of best fit" through the dots. To make a line of best fit do the best you can to line up a ruler through the middle of the dots and draw your line.
- Use your line of best fit to estimate, or roughly calculate, your own height based upon the number of steps you take to walk 6 m. To do this, do the following:
- In your lab notebook, make a data table like Table 2, below, to record your new data.
- Walk from one end to the other of your 6 m course while counting the number of steps you take. Write down the number of steps you took in your new data table.
- Find the number of steps on your graph and find the place on the graph where it crosses your line of best fit. Make a dark star on this point. Look over to the left to see which height the star matches up with and this will be an estimate of your height. Write this information in your new data table.
Number of Steps Taken | Estimation of My Height (cm) |
My Actual Height (cm) |
Difference in Height (cm) |
- Ask your parent to measure your actual height with the tape measurer (in cm). Write this in your new data table.
- Calculate the difference between your estimated height and the actual height by subtracting one from the other. Write the difference (in cm) in your new data table. How accurate was your estimate? Do you think there is a reliable relationship between the height of an individual and the pace that they walk? How can this information be used?
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I Did This Project! Please log in and let us know how things went.Variations
- Make another data table for estimating the height of a person based upon the "standard" graph that you developed. It should have a place for the number of steps, the estimated height, and the actual height. Now ask for more volunteers and try to guess their height based upon your graph and the number of steps they take. How often are you correct? How accurate are your estimates?
- One factor in developing a standard in this experiment is over which distance you choose to measure the number of steps a person takes. Do you think that longer or shorter distances would give a better, more accurate standard? Do an experiment by developing separate standards, each using a different distance over which the steps are counted (3 meters, 6 meters, 9 meters, etc.). Which one gives the most accurate measurement?
- You can develop standard curves for the role of height (or some other variable) in other sporting activities. Try the height a person can jump, the distance a person can jump, the distance a person can throw a ball, etc.
- How does the speed of walking affect the number of steps required to go a certain distance? You can do an experiment where you walk the 6 meter distance slowly, moderately fast, or very fast to see if the number of steps changes with speed. Will there be more steps for slower or faster walking? What about running? How might this relate to momentum?
- The human body has many other interesting ratios, as is mentioned in the Introduction for this science project. Have an adult help you do some research on other ratios in the human body and come up with an experiment like the one in this science project to investigate them. For some more ideas on this topic, check out the website listed in the Bibliography on Simple Ratios of the Human Body.
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