Cards | 10 |

Focus | Motion |

Topics | Acceleration, Momentum, Vectors, Velocity |

Acceleration is the rate of change of velocity per unit of time. In physics, the **delta symbol** (\(\Delta\)) represents change so the formula for acceleration becomes \(\vec{a} = { \Delta \vec{v} \over t }\)

Momentum is a measure of how difficult it is for a moving object to stop and is calculated by multiplying the object's **mass** by its **velocity**: \(\vec{p} = m\vec{v}\). Like velocity, momentum is a vector quantity as it expresses force applied in a specific direction.

Velocity and displacement are **vector quantities** which means each is fully described by both a **magnitude** and a **direction**. In contrast, **scalar quantities** are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: \(\vec{v}\)

Velocity is the rate at which an object changes position. Rate is measured in time and position is measured in **displacement** so the formula for velocity becomes \(\vec{v} = { \vec{d} \over t } \)