## Most recent change of Acceleration

Edit made on November 29, 2008 by GuestEditor at 13:44:16

Deleted text in red / Inserted text in green

WW
In physics, acceleration is how quickly one's speed (more correctly, velocity)
changes. Since velocity is usually given in metres per second, and we ask how
quickly that changes, we have to say that the rate of change of velocity is
expressed as (metres/second) per second, or metres per second squared.

In symbols, EQN:ms^{-2}.

Sir IsaacNewton Isaac Newton expressed three laws of motion, the second of which says that
the acceleration of an object is proportional to the force being applied, and
inversely proportional to its mass. For a given mass, applying twice the
force results in twice the acceleration, while for a given constant force,
an object that is twice as heavy will accelerate half as fast.

Why then do heavier objects not fall more slowly?

Because the force due to gravity is proportional to the mass of the object.
Thus for an object that is twice as heavy the force is twice as great, and
so these effects exactly balance, and the acceleration due to gravity is
the same for all objects (ignoring such effects as air resistance).