# Homework Help: Pistons and pressure question help

1. Jan 27, 2008

### lollol

area of a piston is 0.02

what is the AVERAGE pressure exerted on 2 equal pistons if the force is 25 N

P = F/A

do you just combine the areas.. and divide the combined area by F

i just did... pressure = F/Area of 1 piston

and since it said average... they both give the same pressure.. add them up.. divide by two, and end up with the same pressure. Is this wrong?

I didn't combine the areas

2. Jan 27, 2008

### kateman

can you write out the entire, complete question?

3. Jan 27, 2008

### lollol

The force exerted on 2 pistons was 10 N.. lets say
Area of each piston is 2m

What was the average pressure on the pistons? The word average confused the heck out of me...

so I found the pressure on each... added them.. divided by 2... and got the same pressure

Was I supposed to add the two areas?

4. Jan 28, 2008

### kateman

think about it. what has changed?

if you were to divide pressure by half then you must also divide F/a by half as well otherwise the equation wont work. if you do that then nothing has changed and your getting no where.

and just to give you an even bigger hint: force isnt changing either.

hope this helps