# Urgent Aero question help

1. May 30, 2012

### lauraosborn

Urgent Aero question help!!

I can't seem to do this question without the static pressure given.
Can someone show me the workings and how it is done?

I can't seem to do this question without the static pressure given. Can someone show me the workings and how it is done? Question >> hxxp://postimage.org/image/cp3w7a7jl/ [Broken]

Last edited by a moderator: May 6, 2017
2. May 30, 2012

### Travis_King

Re: Urgent Aero question help!!

Rules is rules, you've got to show your attempt. What have you tried. List your knowns, your equations, etc. Then we can help fill in the missing pieces.

3. May 30, 2012

### lauraosborn

Re: Urgent Aero question help!!

formula i am thinking of using is True air speed, V^2= (2a^2)/(1.4-1) x [(total pressure/ static pressure)^((1.1-1)/1.4) -1]

but since only total pressure of 84.2 KPa is given, i cannot get the true air speed without static pressure. and other formulas for equivalent airspeed and calibrated airspeed also needs static pressure to calculate

4. May 30, 2012

### Travis_King

Re: Urgent Aero question help!!

You know the pressure altitude, though, no? That number comes from an existing equation.

5. May 30, 2012

### lauraosborn

Re: Urgent Aero question help!!

erm, is there a formula that links the pressure altitude to static pressure? (sorry if i sound dumb >_<)

6. May 30, 2012

### Travis_King

Re: Urgent Aero question help!!

Check this link out

(Oops, looks like your equation is the same anyway, either way, it's a good link).

As far as the static pressure goes, here's a good estimate: Engineering Toolbox

7. May 30, 2012

### lauraosborn

Re: Urgent Aero question help!!

will do, thanks alot for your help