Acceleration
1. In mechanics, acceleration is the rate of change of the velocity of an object with respect to time.
2. Acceleration is the rate of change of velocity per unit of time.
Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by the orientation of the net force acting on that object. The magnitude of an object's acceleration, as described by Newton's Second Law, is the combined effect of two causes:
the net balance of all external forces acting onto that object – magnitude is directly proportional to this net resulting force;
that object's mass, depending on the materials out of which it is made – magnitude is inversely proportional to the object's mass.
The SI unit for acceleration is metre per second squared (m⋅s−2,m/s^2 ).
Lehrman, Robert L. (1998). Physics the Easy Way. Barron's Educational Series. ISBN 978-0-7641-0236-3. p.27.
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