Page 2 - Lesson Notes

Types of Acceleration

Acceleration is defined as the rate of change of velocity and is an example of a vector
quantity. Following are the types of acceleration:

 Uniform acceleration: When an object is travelling in a straight line with an
increase in velocity at equal intervals of time, then the object is said to be in
uniform acceleration. Free falling of an object is an example of uniform
acceleration.
 Non-uniform acceleration: When an object is travelling with an increase in
velocity but not at the equal intervals of time is known as non-uniform
acceleration. Bus moving or leaving from the bus stop is an example of non-
uniform acceleration.
 Instantaneous acceleration: Acceleration of an object at any instant of time is
known as instantaneous acceleration.

⚫Positive Acceleration

When the velocity of an object increases, the acceleration is positive. In this case,
the acceleration is in the direction of Velocity.

⚫ Negative Acceleration

When the velocity of an object decreases with time it has negative Acceleration.
Negative acceleration is also called deceleration Its directions is opposite to the
direction of Velocity.

⚫ Zero Acceleration

If the velocity of the object does not change with time, it has zero acceleration.

Average acceleration

The average acceleration over a period of time is defined as the total change in velocity
in the given interval divided by the total time taken for the change. For a given interval of
time, it is denoted as ā.

Mathematically,