Materials:
* The rock
* Graduated cylinder (large enough to hold the rock)
* Water
* Scale
Procedure:
1. Measure the mass: Use the scale to determine the mass of the rock in grams.
2. Measure the volume:
* Water displacement method:
* Fill the graduated cylinder with a known volume of water. Record the initial water level.
* Carefully lower the rock into the graduated cylinder, making sure it is fully submerged.
* Observe the new water level. The difference between the initial and final water levels represents the volume of the rock.
3. Calculate the density:
* Density = Mass / Volume
* Divide the mass of the rock (in grams) by the volume of the rock (in milliliters or cubic centimeters).
Example:
Let's say:
* The rock's mass is 50 grams.
* The initial water level in the graduated cylinder is 20 ml.
* The final water level after adding the rock is 40 ml.
* Volume of the rock = Final volume - Initial volume = 40 ml - 20 ml = 20 ml
* Density = 50 grams / 20 ml = 2.5 g/ml
Important Notes:
* Accuracy: The accuracy of your density measurement depends on how carefully you measure the mass and volume.
* Units: Make sure to use consistent units for mass and volume (grams and milliliters or cubic centimeters are common).
* Special cases: If the rock is porous (has holes) or absorbs water, the water displacement method may not be accurate. Other methods, like using a displacement tank or a pycnometer, might be necessary.
