A-level Mathematics/Advanced/Basic Mechanics/Basic Concepts in Mechanics

Basic Concepts in Mechanics Time - frequently referred to as 't' and generally measured in seconds (s), but any units of time are fine, e.g. hours, minutes. See Time for a reasonable definition - or look at your watch for a while. This is time passing.... Distance - frequently referred to as 'd' and generally measured in meters (m). Also known as length. This is how far away one object is from a specified reference point. The reference point may be another object or the origin (insert link). Speed - frequently referred to as 's' and generally measured in meters per second (m/s), but any units of measurement and time are fine, e.g. km/h, feet/minute. This is how fast an object is travelling - i.e. how much distance an object has moved in a given time. Direction is not relevant for speed - but q.v. velocity. Speed is a scalar (link). Velocity - frequently referred to as 'v' and generally measured in meters per second (m/s), but again any units of measurement and time are fine, e.g. km/h, feet/minute. This is how fast an object is travelling in a given direction- i.e. how much distance an object has moved in a given time. Direction is relevant for velocity - but q.v. speed. Velocity is a vector (link) in that it has speed plus direction (so more than one co-ordinate is required to define the velocity). Acceleration - frequently referred to as 'a' and generally measured in meters per second squared (m/s2), but again any units of measurement and time are fine, e.g. km/h2, feet/minute2. This is the rate of change in velocity over time Mass - frequently referred to as 'm' and generally measured in kilogrammes(kg). Mass is the amount of matter in an object. It is not the same as weight, except when the object is under the influence of gravity. Specifically an object always has mass, but for example in space it will have no weight. Momentum Also needs to cover : moments of inertia and force and ....(feel free to add suggestions). See also Definitions