Purpose

To investigate the effect of air resistance on moving objects with the same mass.

Materials Fundamentals - Is it the Gravity or is it the Air? Skills - Conducting an Experiment balance 2 sheets of paper 2 squares of aluminum foil (6x6) stopwatch

Colorado Rockies - Coors Field

Records show that the Colorado Rockies hit many more home runs on their home field in Denver than when they are on the road. They also have much more success at bat at home than away. This might seem normal. When players are on their home fields they often do better. But, the Denver ballpark is special. It has been called "the greatest hitter's park in baseball history" because some players are able to hit home runs in Denver but nowhere else. And, homeruns hit in Denver travel farther than home runs hit anywhere else. The questions are why, and what should be done about it?

 

Initial Speed of ball (m/s) Distance traveled at Sea Level (m) (Elevation 0m) Distance traveled in Denver (m) (Elevation 1609m): Distance traveled in Mt. Everest (m) (Elevation 8848m): Distance traveled in a vacuum (m) 35 72.9 77.2 94.5 123.1 40 85.3 91 115.2 160.8 45 96.9 104.2 135.7 203.5 50 107.7 116.5 155.8 251.2

1. What trends do you notice? Hint: Look at the distances traveled by the ball as speed increases. Look at the distances traveled by the ball as altitude increases.
2. What do you notice about the distance a ball travels in a vacuum compared to other locations? Why do you think this happens?

You are a member of a committee working for the Baseball Commissioner. Your committee has been asked to investigate and report on the science that explains why the number of home runs is higher in Denver than in other U.S. cities. You have also been asked to suggest how the effect of high altitude might be eliminated or lessened.

Your committee has decided to answer this question:

What effect does air resistance have on the speed of objects traveling through the air?

Procedure

There are three jobs that need to be done: timer, observer, and recorder. Divide up the jobs but rotate them so that everyone gets to try each job.

First, measure how long it takes for a sheet of paper to fall to the floor from a certain height.

Before you do anything else, read Skills - Conducting an Experiment.

Next, select something that you can do to the paper that might make it fall faster. Do not change the mass or the height of the drop! Remember that to fall means free fall. Do not throw the paper. Test your idea and record the results.

Now do the same experiment with a sheet of aluminum foil.

Conclusion

Write a letter to the Baseball Commissioner explaining why there are more home runs in Denver than in other cities. Include a suggestion to the Commissioner for eliminating the effect of altitude. Explain why you think your idea will work. Make sure to discuss the science behind your idea.

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This activity was developed by the Event-Based Science Institute with generous support from the Cal Ripken, Sr. Foundation. A teacher version of this and all other baseball/physics activities is available free from the EBS Institute. This activity was written by Laurie Bricker, science teacher at Sligo Middle School, Silver Spring, MD.