IB Physics SL B.3.6 Molecular pressure model Question Bank

Practise IB Physics SL B.3.6 by linking gas pressure to molecular speed, collision frequency and momentum transfer at container walls.

Exam points

Explain pressure changes through molecular speed, collision frequency and momentum transfer at the walls.
Use kinetic theory to connect temperature, mean kinetic energy and pressure in a fixed-volume gas.

[Maximum number: 1]

A solid cylinder of height h and density $\rho$ rests on a flat surface.

Figure for Question B.3.6—Molecular pressure model question 1 — IB Physics SL

A tube of constant circular cross-section, sealed at one end, contains an ideal gas trapped by a cylinder of mercury of length 0.035 m . The whole arrangement is in the Earth's atmosphere. The density of mercury is $1.36 \times 10^{4} \mathrm{~kg} \mathrm{~m}^{-3}$ .

When the mercury is above the gas column the length of the gas column is 0.190 m .

Outline why the gas particles in the tube hit the mercury surface less often after the tube has been rotated.

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B.3.6—Molecular pressure model question 1