Physics: Motion, Force, Energy and Basic Electricity
Mechanics
Understand units and measurement, scalars versus vectors, speed and velocity, acceleration, Newton's three laws, momentum, work, power, and energy. Know that work equals force times displacement in the direction of force, and that energy is conserved but transforms between forms. Learn the difference between mass and weight, since weight depends on gravity.
Heat, light and sound
Revise temperature and heat transfer (conduction, convection, radiation), reflection and refraction, and the nature of sound as a mechanical wave that needs a medium. Know that light travels faster than sound, which explains thunder following lightning.
Electricity and magnetism
Learn Ohm's law, series and parallel circuits, conductors and insulators, and basic magnetic effects. In series, current is the same and resistances add; in parallel, voltage is the same and total resistance falls.
Traps and a rule of thumb
Traps: treating mass and weight as identical; assuming work is done whenever force is applied (no displacement means no work); and confusing speed with velocity. Rule of thumb: check units and direction before answering. Worked example: a person pushes a wall with force but the wall does not move; displacement is zero, so work done is zero despite the effort.