Measure the height $h$ of the test-tube shown in Fig. 1.1 to the nearest $0.1\,\text{cm}$.
Measure the external diameter $d$ of the test-tube shown in Fig. 1.1.
Explain why it is necessary for the student to make sure that the blocks are parallel to each other.
Calculate the external volume $V_E$ of the test-tube with $V_E = 0.79\,d^2 h$.
Enter the reading $V_I$ on the measuring cylinder; this gives the internal volume of the test-tube.
Calculate the volume $V_G$ of the glass in the test-tube by applying $V_G = V_E - V_I$.
Suggest one possible source of inaccuracy when measuring the internal volume of the test-tube $V_I$.
Record $m$ correct to the nearest gram.
Use your results from (g)(i) and (e) to find the density $\rho$ of the glass used to make the test-tube with $\rho = \frac{m}{V_G}$. Include the unit in your answer.