1. Law(s) : -- Boyle’s Law Charles’ Law Pressure Law
Gas Laws
Law(s) : -- Boyle’s Law
Charles’ Law
Pressure Law

2. Pressure and Volume
Boyle’s law

3. How is pressure defined?
Pressure is defined as the
the force per unit area
Pressure = Force / Area

4. To reduce the pressure on the snow, increase the area

6. The unit of pressure = N / m2 = Pascal (Pa)
Pressure = Force / Area
The unit of pressure = N / m2
= Pascal (Pa)
Atmospheric Pressure = Pa
= 100 kPa

7. Bourdon Gauge

8. The whistle uncoils when air is blown into it.

9. Bourdon Gauge

10. Pressure - Volume (P-V) relation of a gas
When studying the behaviour of gases, there are three quantities to consider:
Pressure
Volume
Temperature

11. Consider: Variation of volume with pressure

13. Pressure
Volume
The volume of a fixed mass of gas at a constant temperature is
inversely proportional to the pressure.

14. Pressure & Volume
P  1/V
P = constant / V
P V = constant

15. Boyle’s law The volume of a fixed mass of gas is
inversely proportional to its pressure
(that the temperature is held constant)

16. Pressure & Volume P V = constant P1 V1 = constant eg. 20 x 27 = 540
P1 V1 = P2 V2 = P3 V3