What is the meaning of pressure?
Apply the result from a(i) to demonstrate that the SI base units for pressure are $\text{kg m}^{-1} \text{s}^{-2}$.
A pipe laid horizontally has length $L$ and a circular cross-section with radius $R$. A liquid with density $\rho$ moves through the pipe. The mass $m$ of liquid passing through the pipe in a time $t$ is given by $m = \frac{\pi (p_2 - p_1) R^4 \rho t}{8 k L}$, where $p_1$ and $p_2$ are the pressures at the two ends of the pipe and $k$ is a constant. Find the SI base units of $k$.
An experiment is carried out to find the value of $k$ by measuring the other quantities in the equation in (b). The values of $L$ and $R$ each carry a percentage uncertainty of $2\%$. State and explain, using numbers, which of these two quantities makes the larger contribution to the percentage uncertainty in the calculated value of $k$.