## Measuring

Working with formulas to solve problems

Determining the radius of a circle given the circumference

Calculating the volume of a sphere

Averaging data

Comparing theoretical and experimental results

Writing a Conclusion

## Cloth tape measure

12 inch round balloons

calculator

1. Stretch the balloon by blowing it up several times.

2. Inhale as much air as possible and exhale the air into the balloon. Work hard

to empty your lungs completely.

3. Have another student measure (in centimeters) the circumference of the

balloon. Make sure the balloon is round and the measurement is from the

largest region.

4. Record the circumference

5. Repeat the procedure four times.

6. Calculate the average circumference from the five trials.

7. Using the average circumference and the formula for finding circumference,

compute the average radius of the sphere (your balloon).

8. Calculate the volume of the sphere.

9. Assuming 1cc of air = 1 ml of air, the volume of the sphere is your

experimental lung capacity.

10. Compute your theoretical lung capacity using the formula given below.

h is your height in centimeters

a is your age in years

11. Compare the theoretical lung capacity to the experimental lung capacity.

Write a paragraph, on your own paper, explaining the comparison.