Syringe: Find force given volume and pressure

[kamhogo]

Homework Statement

A 60 mL syringe filled with air is connected to a pressure sensor. The latter reads 100kPa.
You then push on the piston until it stops moving. You now have 30 mL and the pressure sensor reads 200kPa.

What force is used to keep the syringe rubber at the 30 mL mark?

Homework Equations

P=F/A

The Attempt at a Solution

I'm lost. I need the surface of the rubber ( not given) or at least the length of the syringe ( A= V/L) to find the force. A hint please?

 

[Bystander]

You've put your finger on the missing/necessary information; reread the problem statement to be certain of that fact.

 

[TSny]

You've put your finger on the missing/necessary information