MMSR 1101 Lesson 10: Mass, Weight and Density

Comprehensive flashcards covering key concepts, formulas, units, definitions, and worked calculation examples from MMSR 1101 Measurement Lesson 10 on Mass, Weight, and Density.

Which is heavier: $1\text{ kilogram}$ of cotton wool or $1\text{ kilogram}$ of rocks?

Neither, because $1\text{ kilogram}$ of any substance has the same mass regardless of what the substance is.

What is the scientific definition of mass?

Mass is the amount of matter in a real body or object, where matter refers to the substance it is made up of.

How does mass differ fundamentally from weight?

Mass is the amount of matter in an object and does not change with location, whereas weight is the amount of gravitational pull on that mass and changes when gravity changes.

According to the lecture, what would a human with a mass of $50\text{ kilograms}$ weigh on Earth versus on Mars?

The human would weigh $110\text{ pounds}$ on Earth, but only $42\text{ pounds}$ on Mars due to the difference in gravitational pull.

Based on the balance scale shown in the diagram, what is the weight of the eggplant?

$600\,g$ (balanced by the $500\,g$ and $100\,g$ weights on the opposite pan).

What is the formula used to calculate the weight of an object?

$W = m \times g$, where $W$ is Weight in newtons ($\text{N}$), $m$ is Mass in kilograms ($\text{kg}$), and $g$ is Gravitational field strength in newtons per kilogram ($\text{N/kg}$).

Why is weight classified as a force, and what is its resulting unit?

Weight is classified as a force because multiplying mass ($\text{kg}$) by gravitational field strength ($\text{N/kg}$) simplifies to newtons ($\text{N}$).

What is the definition of density?

Density is the degree of compactness of a substance, referring to how compactly packed a solid is.

As illustrated by the seesaw diagram comparing equal volumes of two substances, which substance has greater weight?

The substance with higher density has more weight than the substance of lower density for an equal volume.

What are the three algebraic formulas relating mass, density, and volume?

$\text{Density} = \frac{\text{Mass}}{\text{Volume}}$, $\text{Mass} = \text{Density} \times \text{Volume}$, and $\text{Volume} = \frac{\text{Mass}}{\text{Density}}$.

A cuboid measures $10\,cm \times 10\,cm \times 10\,cm$ and has a mass of $2000\,g$. What is its density?

$2\,g/cm^3$ (calculated as volume $= 1000\,cm^3$, and density $= \frac{2000\,g}{1000\,cm^3} = 2\,g/cm^3$).

If a substance has a mass of $6\,g$ and a volume of $3\,mL$, what is its calculated density?

$2\,g/mL$ (calculated as $\frac{6\,g}{3\,mL} = 2\,g/mL$).

In the worked example on slide 15, how is mass calculated given a substance's density and volume?

Mass is found using $\text{Mass} = \text{Density} \times \text{Volume}$, which yielded a calculated mass of $136.3\,g$.

Based on the provided multiple choice slide, what is the density of the cube with a mass of $12\text{ grams}$ and dimensions measured by a micrometer?

C. $9.6\,g/cm^3$

How do you calculate the density of a cone or pyramid when only its base, perpendicular height, and mass are provided?

First determine the volume using $V = \frac{1}{3} \times \text{base area} \times \text{perpendicular height}$, and then calculate density using $\text{Density} = \frac{\text{Mass}}{\text{Volume}}$.