Internal energy in the particle model
Internal energy in the particle model

A system is the object or gas sample we choose to study. Its internal energy is the total random kinetic energy and potential energy of its particles.
Step-by-step lessons on Edexcel A Level Physics Internal energy and kinetic theory. Each one builds up to exam-style questions. Physics is one of the most mathematically demanding A Levels -- at least 40% of the marks across the three papers require maths skills at Level 2 (GCSE) standard or above, so build calculation and graph-handling fluency alongside the conceptual content from the start.