Predict mass from density
Predict mass from density using supplied evidence and a solved model.
About 25 minutes, plus any extended practice
Supplied materials
- All measurements and observations below are supplied classroom examples. They are not data from actual learners or a claim about a particular real site.
- Paper or browser document; an ordinary calculator is optional.
- Rule: Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. Formula: a*b. Variable key: a = density (g/cm³), b = volume (cm³)
- Distinct worked inputs and result: A distinct uniform model has density 3 g/cm³ and volume 5 cm³: 3×5=15 g.
- Assessment case 1: Supplied case 1: density (g/cm³)=2; volume (cm³)=8, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
- Assessment case 2: Supplied case 2: density (g/cm³)=3; volume (cm³)=7, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
- Assessment case 3: Supplied case 3: density (g/cm³)=4; volume (cm³)=9, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
- Assessment case 4: Supplied case 4: density (g/cm³)=5; volume (cm³)=6, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
- Assessment case 5: Supplied case 5: density (g/cm³)=6; volume (cm³)=4, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
- Assessment case 6: Supplied case 6: density (g/cm³)=2.5; volume (cm³)=12, using the explicitly named quantities. Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. What result follows?
Learn the idea
For a uniform sample at stated conditions, mass scales with volume. A density model can predict mass, but it does not identify every unknown material uniquely.
Mass equals density in grams per cubic centimeter multiplied by volume in cubic centimeters. The formula in the supplied model is a*b. Variable key: a = density (g/cm³), b = volume (cm³). Multiply density by volume. The volume unit must match the density denominator.
A distinct uniform model has density 3 g/cm³ and volume 5 cm³: 3×5=15 g. Use the stated uniform-material assumption. Track the quantity and unit before calculating. Explain the meaning of a positive, negative or fractional result when relevant. A numerical answer supports the stated model calculation; broader claims require the additional measurements and assumptions described here.
- Name the measured quantities and their units before substituting values.
- Write the stated rule and use the variable key to match each symbol to its explicitly named quantity.
- Calculate each supplied case separately, keeping intermediate arithmetic and the result unit.
- Explain the result in context and identify the assumption that would invalidate direct use of the rule.
See the method in action
Worked distinct example: A distinct uniform model has density 3 g/cm³ and volume 5 cm³: 3×5=15 g. Method: identify the quantities in the stated rule, substitute using compatible units, and perform the operations in the correct order. Multiply density by volume. The volume unit must match the density denominator. Interpret the final unit and keep the model assumption visible; this calculation is not a measurement of a real learner or site.
Check your reasoning
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Helpful tips
- Multiply density by volume.
- The volume unit must match the density denominator.
See the answer and explanation
16 g
Substitute the supplied values: (2)*(8) = 16 g. Multiply density by volume. Use the stated uniform-material assumption.
Take it further
Changed-input task: use the same stated model with density (g/cm³)=3; volume (cm³)=8. Expected result: 24 g. Explain what changes and keep this assumption: Use the stated uniform-material assumption.
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More practice: try new cases
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Check the subject sources
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