This definitions covers Key Definitions within Gas Pressure & Temperature for GCSE Physics. Revise Gas Pressure & Temperature in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 6 of 12
Practice
13 questions
Recall
30 flashcards
📖 Key Definitions
Gas pressure: The force per unit area exerted by gas particles colliding with container walls. Units: Pascals (Pa) or N/m².
Absolute zero (0 K): The theoretical minimum temperature (−273°C) at which particles have minimum kinetic energy and gas pressure would be zero.
Kelvin (K): The SI unit of absolute temperature. T(K) = T(°C) + 273. Used in gas law calculations.
Upthrust: The upward force on an object submerged in a fluid, equal to the weight of fluid displaced. If upthrust ≥ weight, the object floats.
Atmospheric pressure: The pressure exerted by the atmosphere on objects at Earth's surface, approximately 100,000 Pa (100 kPa). Decreases with altitude as there is less air above.