Precision laboratory balance
Measures specimen gravitational mass M with a resolution of 0.01 g.
Physics / Density of solids
FREE TO EXPLOREEXPERIMENT 13 · PHYSICS LABORATORY
Measurement of mass, volume and determination of the density of solids
Determine the density of pure copper specimens by linear regression of mass against volume using precision balance and displacement measurements. Explore a virtual apparatus, collect readings and analyse a graph.
CHANGE · OBSERVE · MEASURE
Your virtual workbench.
SPECIMEN MASS M—
MEASUREMENT STATUS
Ready for a virtual observation.
Adjust the apparatus, then take a reading.
Readings are generated by an ideal model. The diagram is schematic and is not to scale.
Simulation assumptions and limits
The simulation assumes an ideal homogeneous copper specimen without internal casting porosity, oxide films, or surface contamination. Readings in this virtual module reflect ideal copper (ρ = 8960 kg m⁻³) with standard rounding to 0.01 g on balance mass and 0.1 cm³ on volume.
Know your apparatus.
Graduated cylinder and Eureka displacement can
Measures volume of regular or irregular solids by water displacement with anti-meniscus correction.
Vernier calipers
Measures diameter and height of cylindrical specimens to calculate volume independently.
Set of calibrated copper specimens
Provides homogeneous test cylinders of graded volumes from 5.0 cm³ to 60.0 cm³.
FOLLOW THE METHOD
A reason behind every step.
Determine the density of pure copper specimens by linear regression of mass against volume using precision balance and displacement measurements. Suggested independent settings: 10.0, 20.0, 30.0, 40.0, 50.0 cm³.
Inspect zero calibration of the balance
Release the balance beam arrest and adjust the counterpoise thumb screw until the pointer oscillates symmetrically about the central null mark.
Why this step matters
Zero error in a mechanical or electronic balance introduces an additive constant to every mass measurement, distorting the y-intercept.
Select and measure specimen dimensions
Measure the height and diameter of each cylindrical specimen at three distinct orientations using a vernier caliper to verify geometric regularity.
Why this step matters
Averaging multiple caliper readings across different diameters detects taper, ovality, or surface burrs before immersion.
Perform volumetric displacement in water
Fill a graduated cylinder with distilled water to a reference level, tilt slightly to avoid air entrapment, lower the dry specimen gently on a fine thread, and record the new meniscus level.
Why this step matters
Surface splashing, droplet loss, or air bubbles adhering to the specimen surface cause systematic volume errors.
Dry the specimen thoroughly before weighing
Remove the specimen from the water bath and blot it dry with lint-free absorbent paper before placing it on the balance pan.
Why this step matters
Residual surface water droplets add false mass to the specimen, biasing the measured density upward.
Record equilibrium balance readings
Place the dry specimen at the center of the pan, slide the poise weights along the beams until equilibrium is restored, and read the total mass to the nearest 0.01 g.
Why this step matters
Off-center pan loading creates knife-edge friction and torque, reducing measurement repeatability.
Repeat for the complete series of volumes
Proceed systematically through the graded series of specimen volumes, logging volume V and mass M for linear regression analysis.
Why this step matters
Evaluating multiple independent volumes across a wide dynamic range minimizes leverage bias in the slope determination.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into a result.
Points are your observations. The fit uses SI x and y values before display scaling.
LINEAR FIT · y = mx + b
M = ρV + b
| # | Specimen volume V (cm³) | Specimen mass M (g) | Volume V (10⁻⁶ m³) | Mass M (kg) | Remove |
|---|
No readings yet. Take a virtual measurement and record it.
Calculate it yourself.
CHECK YOUR UNDERSTANDING