Fig. 4.1 shows a large syringe that is sealed at the nozzle by wax. There is a piston inside the syringe. [Figure 4.1] The pressure of the air inside the syringe is equal to atmospheric pressure, 1.0 × 10⁵ Pa. The volume of the air inside the syringe is 1.2 × 10⁻⁴ m³. The area of the end of the piston that is in contact with the air is 3.5 × 10⁻³ m². The friction between the piston and the syringe is negligible.

1. (a)(i)Calculate the force on the piston due to the pressure of the air inside the syringe. force = ........................................................... N[2]
2. (a)(ii)The force on the piston in (a)(i) acts to the right. Explain why the piston does not move to the right.[2]
3. (b)(i)The piston is now pulled to the right by an additional force. The temperature of the air in the syringe does not change. Explain, in terms of particles, why the pressure of the air in the syringe decreases.[3]
4. (b)(ii)Calculate the pressure of the air inside the syringe when the volume of the air is 1.5 × 10⁻⁴ m³. pressure = .......................................................... Pa[2]

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