Suggest a piece of apparatus that can measure the diameter of this bead more accurately than a ruler.
Use a ruler to determine the diameter of the glass bead in Fig. 3.2.
Explain the way you measured the diameter as accurately as possible. You may draw on the diagram if you wish.
Describe how you would determine the combined volume of the 50 glass beads. State which apparatus you would use and explain the way it is used. You may include a diagram if you wish.
State one precaution used to ensure that the volume value is accurate.
The beads have a total volume of $196\text{ cm}^3$ and a total mass of $523\text{ g}$. Use the equation $\text{density} = \frac{\text{mass}}{\text{volume}}$ to find the average density of the glass in the beads. Give your answer to three significant figures.