Acceleration

From RationalWiki

Jump to: navigation, search

Acceleration is the rate of change of velocity respect to time, and its SI units are m·s-2 (meters per second squared). Mathematically, average acceleration is given by the following equation:

a = \frac{\Delta v}{\Delta t} = \frac{v_f-v_i}{t_f-t_i}

Acceleration in any instant is given by the derivative of velocity with respect to time, or:

a = \frac{dv}{dt}

And remembering that velocity is the derivative of position relative to time:

v = \frac{dx}{dt}

We get:

a = \frac{d \frac{dx}{dt}}{dt} = \frac{d^2x}{dt^2}

Acceleration is the second derivative of position relative to time.

To accelerate a mass object, a force must be applied to it, and the resulting acceleration is directly proportional to the force. Mass, in other words, can be considered at an abstract level as the degree of resistance to acceleration an object displays.

Massless objects (like photons), not needing any force to accelerate them, travel at the speed of light, which is a kind of "universal speed limit", as far as we can tell.

Retrieved from "http://rationalwiki.com/wiki/Acceleration"
Personal tools