Definition of Acceleration

"The rate of change of magnitude of velocity".

More About Acceleration:


  • An object is said to be accelerating if it is changing its velocity.
  • When an object changes its velocity from ‘u’ to ‘v’ in time ‘t’ seconds.
  • Then the acceleration of the object = v - u / t = change in velocity / time
    = final velocity – initial velocity / time
  • The S.I. unit of acceleration is m/s2. - Velocity measured in meters/second, and time in seconds.
    1. ∴ meter / second X second = ms / s square
  • Velocity and speed are not same - velocity is a vector quantity i.e., it has both magnitude and direction.
    1. Example - Body moving with a speed of 30 m/s --- Scalar quantity.
      Body moving with a speed of 30 m/s towards East -- Vector quantity.

Examples of Acceleration:

    An elevator moving up
    Air craft taking off
    Rocket launching

Solved Example on Acceleration:

A skater goes from a standstill to a velocity of 6.7 m/s in 12 seconds. What is the acceleration of the skater?

    A. 5 m/s2
    B. 10 m/s2
    C. 5.6 m/s2
    D. 0.56 m/s2


    Step 1: Write down the equation needed for solving for acceleration. a = v - u / t
    Step 2: Insert the known measurements into the equation.
      The initial speed of the skater was zero since he was not in motion. u=0
    Step 3: The skater finally reached a velocity of 6.7 m/s in 12 seconds, v = 6.7: and t = 12
    The equation will look like this a = 6.7m / s - 0m / s / 12s
    Step 4: Solve. You must solve the change in velocity part of the equation before you divide

    Related terms: Uniform acceleration | Deceleration (or) Retardation
Translate :