Motion, Forces & Energy

Measuring Length In the laboratory, lengths are measured using a ruler (such as a metre ruler). Although this seems straightforward, careful technique is needed…

Scalars and Vectors Physical quantities can be classified into two types based on whether they require direction to be fully described. Scalar Quantity A…

Speed Speed tells us how fast an object is moving - how much distance it covers per unit of time. Speed Distance travelled per unit time. v = s / t v = speed…

Mass Mass A measure of the quantity of matter in an object at rest relative to the observer. Symbol: m | SI Unit: kilogram (kg) Mass is a scalar quantity - it…

Density Density Mass per unit volume of a substance. ρ = m / V ρ (rho) = density (kg/m³) | m = mass (kg) | V = volume (m³) The equation can be rearranged: m = ρ…

What Forces Do A force is a push or pull acting on an object. Forces can: Change the size or shape of an object (e.g. stretching a spring, squashing a ball)…

Moments A moment describes the turning effect of a force about a pivot point. Moment The turning effect of a force about a pivot or axis. It measures how much a…

Momentum Momentum Mass × velocity. p = mv p = momentum (kg m/s) | m = mass (kg) | v = velocity (m/s) Momentum is a vector quantity - it has the same direction…

Energy Stores & Transfers Energy is a fundamental concept in physics that describes the capacity to do work. Energy The ability to do work. It cannot be created…

Energy from the Sun The Sun is the primary source of almost all energy on Earth, providing light and heat energy that drive many natural processes. Key Idea…

Pressure and Forces Pressure describes how concentrated a force is when applied over a surface. Pressure The effect of a force acting over a certain area. It…