An industrial process has an unknown fluid flowing through a small pipe. The pipe is $1\mathrm{.}5$ m

long and $2$ cm in diameter, and the fluid is moving with a velocity of $3$ cm$/$s$.$ To help identify

what the fluid is$,$ a valve at the end of the pipe has been instantaneously closed and the pressure

was measured halfway along the pipe as a function of time.

a$)$ Two possible pressure records are shown below. Is the solid line $($a $35$ kPa pressure increase$)$ or the dashed line $($a $35$ kPa pressure decrease$)$ more likely? Explain your

answer by describing what$$s happening to the fluid in the pipe immediately after the

valve is closed.

b$)$ Based on the pressure record, calculate the velocity of the compression wave in this unknown fluid.

c$)$ Calculate the bulk modulus of the unknown fluid in MPa.

d$)$ Calculate the density of the unknown fluid.

The answers:

b$)$wave speed $=1250$m$/$s

c$)$ bulk modulus $=1460$ MPa

d$)$ density $=934$ kg$/$m$3$

Show all workings to get to the answers above.