Mean square speed
What Mean square speed means in Physics A-Level, as defined for OCR.
Definitions of Mean square speed
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain Mean square speed in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: OCR
A quantity that pressure depends on, related to pressure by p = (1/3)ρ⟨c²⟩, where ρ is density.
The average of the squares of the speeds of the particles, not the square of the average speed.
The average of the squares of the speeds of all particles in a gas, and it is always positive.
Topics that use Mean square speed
- Ideal gases (OCR A-Level)
Related terms
- Absolute zero
- Assumptions of ideal-gas behaviour
- Assumptions of kinetic theory
- Avogadro constant
- Boltzmann constant
- Gas laws
- Ideal gas assumptions
- Internal energy and the ideal-gas model
Using Mean square speed in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Physics questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge