(a(i))[1]
Estimate the mass, in kg, of a wooden metre rule.
(a(ii))[1]
Estimate the volume, in $\text{cm}^3$, of a cricket ball or a tennis ball.
(b)[5]
A metal wire of length $L$ has a circular cross-section with diameter $d$, as shown in Fig. 1.1. Its volume $V$ is described by $V = \frac{\pi d^2 L}{4}$. The diameter, length and mass $M$ are measured so that the density of the wire’s metal can be found. The recorded values are: $d = 0.38 \pm 0.01\ \text{mm}$, $L = 25.0 \pm 0.1\ \text{cm}$, $M = 0.225 \pm 0.001\ \text{g}$. Calculate the density of the metal, including its absolute uncertainty. Present your answer to a suitable number of significant figures.