How to Find the Volume of Gravel by Displacement of Water

Use water to measure the volume of gravel.

It's a simple fact that two objects cannot be in the same place at the same time. If this were not so, you could walk down Fifth Avenue on a warm Saturday afternoon and not once have to dodge or stop to miss another pedestrian coming toward you. Water's no different than you are on Fifth Avenue -- if something wants to be where it is, water usually gets out of the way. This makes the calculation of object volume by displacement easy.

Things You'll Need

• 100 mL graduated cylinder
• Water
• Gravel

Instructions

1. Fill a 150 mL graduated cylinder with water until the bottom curve, or meniscus, of the water level is touching the line on the cylinder marked "50."

2. Add a small amount of fine gravel to the graduated cylinder. Do not add so much gravel that the water level rises past the graduated marks along the side of the cylinder.

3. Note the bottom curve of the water level. Count the number of short marks between it and the nearest numbered line below. For example, the bottom curve of the water touches the third line above the line on the cylinder marked "70."

4. Add the number of lines you count to the number of the nearest marked line below them. For example, 3 + 70 = 73.

5. Subtract 50 from this number. For example, 73 - 50 = 23. The volume of the gravel is therefore 23 cubic centimeters.

References

• Georgia State University; Hyperphysics: Archimedes' Principle; C. R. Nave; 2011
• Frostburg State University: How Can Density Be Found by Water Displacement?
• University of Wisconsin, Madison: Reading the Volume from a 100-mL Graduated Cylinder
• Fordham Preparatory School: Water Displacement Method
• "Physics for Scientists & Engineers with Modern Physics"; Douglas C. Giancoli; 2008