Choose an exam and explore concepts through visual explanations, topic maps and revision checks. Open the full chapter notes whenever you need more detail.
THE VISUAL LEARNING STUDIO
See the idea. Understand the connection.
35 visual explanations across 29 chapters, with topic maps throughout the library.
The chapter index will grow as additional notes are prepared. Chapters shown here are a learning collection, not a claim that the entire exam syllabus is complete.
SEE IT. CONNECT IT. EXPLAIN IT.
Understand the chapter visually
Start with the topic map, then open each explanation below. Detailed concept diagrams are being added to this chapter.
Use Recall mode to hide explanations; tap or focus a card to reveal one. Expand any diagram for a larger view.
Study the expanded notes and the credited detailed textbook lessons. The current chapter index covers core topics; it is not a claim of exhaustive coverage of every examination syllabus. Check the official syllabus and primary references.
Work, Energy and Power — lesson overview
Work and kinetic energy
For a constant force, work is the scalar product W = F s cosθ, where θ is the angle between force and displacement.
Kinetic energy for non-relativistic translation is K = ½mv². The net work–energy theorem relates net work to change in kinetic energy.
A force perpendicular to instantaneous displacement does no work on that motion, even though it may change direction.
Potential energy and conservation
Potential energy is associated with a system’s configuration under conservative interactions; near Earth’s surface ΔU = mgΔh under the usual constant-g approximation.
Mechanical energy is conserved when only conservative forces perform work in the system being modelled. Non-conservative work can change mechanical energy.
Energy conservation is broader than mechanical-energy conservation: friction can convert organised mechanical energy into internal energy.
Power and example
Power is the rate of doing work or transferring energy: average P = W/Δt. One watt is one joule per second.
Raising 5 kg by 2 m at constant speed with g = 10 m s⁻² requires a 100 J increase in gravitational potential energy. In 4 s, average useful power is 25 W.
Efficiency compares useful output with input under clearly stated definitions; energy losses do not mean energy disappears from the complete system.
