Define the forms(a) Acceleration, (b) Retardation, (c) Variable accelaration, (d) Average acceleration, (e) Uniform acceleration, (f) Instantaneous acceleration.
Acceleration : It is defined as the ratio of change in velocity & the corresponding time taken by the mirror object i.e.It is vector quantity.It is either positive or negative.Negative acceleration is Retardation.Unit-m/s2 in SI & cm/s2 in CGS system.Uniform acceleration. An object is said to be moving with a uniform acceleration if its velocity changes by equal amounts in equal intervals of time. Variable acceleration. -An object is said to be moving with a variable acceleration when its velocity changes by unequal amounts in equal intervals of time.The velocity time graph of a body having variable acceleration is represented by a curve.Average acceleration. When an object is moving with a variable acceleration, then the average acceleration of the body is defined as the ratio of the total change in velocity during motion to the total time taken, i.e(iv) Instantaneous acceleration:(a) If a body is moving with a variable acceleration, then the acceleration of a body at the given instant of time is called instantaneous acceleration.