# I Volumetric flow rate and Force

1. Nov 30, 2017

Does Pressure multiplied by volume multiplied by volumetric flow rate equal Force?

2. Nov 30, 2017

### Staff: Mentor

Welcome to the PF.

What do the units work out as?

3. Nov 30, 2017

N/m2 x m3 x m3/s so Nm4/s

4. Nov 30, 2017

### Staff: Mentor

Can you describe each term? It looks like you have an extra m^3 in there...?

5. Nov 30, 2017

the equation is pAdeltaL * dv/dt

so pressure times volume times change in length time volumetric flow rate

6. Nov 30, 2017

### jbriggs444

The equation has pressure p.
Area A
Incremental length delta L
Incremental volume dv/dt

Are you not double-dipping? You have both area times incremental length and incremental volume?

7. Dec 3, 2017

In terms of a flowing fluid, there are multiple terms that contribute to force. One of them happens to be from pressure and looks like $pA$ (or rather $\int p\;dA$). Your term has a bunch of extra stuff in it. My suspicion is that you are trying to combine too many physical effects into a single term rather than separating their contributions. Specifically, pressure effects and momentum change effects must be treated separately (though there are relationships between some of those variables).