Define pressure.
Use the answer to (a)(i) to show that the SI base units of pressure are 
A horizontal pipe has length 
and a circular cross‑section of radius 
. A liquid of density 
flows through the pipe. The mass 
of liquid flowing through the pipe in time 
is given by:
where 
and 
are the pressures at the ends of the pipe and 
is a constant.
Determine the SI base units of .
.
.
