# Acceleration

## What is Acceleration ?

“**Acceleration is the rate at which something changes its speed**“. It is the rate of change of velocity. It is the change of velocity per time. For example, if you are driving at 50 miles per hour and increase to 60 miles per hour, you have experienced an acceleration of 10 miles per hour per hour. If you are travelling at 100 miles per hour and increase to 110 miles per hour, you have experienced an acceleration of 10 miles per hour per hour.

- Unit of acceleration- m/s
^{2} - Dimension of acceleration- [L T
^{-2}]

**There are four types of acceleration**:

- Average Acceleration
- Instantaneous Acceleration
- Uniform Acceleration
- Non-Uniform Acceleration

#### Average Acceleration

When the velocity of an object is changing at each instant of time, we can say that the velocity is changing with an average acceleration. The average acceleration of an object is a number which tells us the average rate of change of velocity of an object. The average acceleration of an object is the change in velocity of the object in a given time divided by the time.

#### Instantaneous Acceleration

The acceleration is measured as a change in velocity per unit time. However, acceleration is not measured at the same time that velocity is measured. The acceleration is measured at a much later time than the velocity is measured. When velocity is measured, the object may have already moved a significant distance. A common misconception is that the average acceleration is the same as the instantaneous acceleration but an object that is accelerating is not moving at a constant velocity. An object that is accelerating can be moving at any velocity.

#### Uniform Acceleration

Uniform acceleration refers to any constant acceleration which is independent of the mass of the object. The acceleration of an object with uniform acceleration is the same in magnitude regardless of the mass of the object. This acceleration is constant and is the same whenever the object is at the same height above the ground. The acceleration of an object with uniform acceleration is independent of the mass of the object. The acceleration of an object with uniform acceleration is the same in magnitude regardless of the mass of the object. This acceleration is constant and is the same whenever the object is at the same height above the ground. Something with a positive acceleration is speeding up, while something with a negative acceleration is slowing down.

#### Non-Uniform Acceleration

Non-uniform acceleration is the phenomenon where the acceleration of an object varies depending on its position. The object undergoes different accelerations in different points of its path. The object may undergo acceleration in the positive direction, in the negative direction or in both directions. The acceleration can be constant during each interval or it can be changing during each interval. For example, the roller coaster undergoes acceleration in the positive direction while climbing the hill and in the negative direction while descending down. Acceleration is constant in the positive direction while climbing and in the negative direction while descending.

### Difference between Velocity and Acceleration ?

Velocity is the rate of change of displacement with respect to time while acceleration is the rate of change of velocity with respect to time. The velocity of an object is the rate at which the object moves but acceleration is the rate of change of velocity with respect to time. Velocity is a vector quantity both magnitude and direction are required to define it while acceleration is a scalar quantity only magnitude is required to define it. If a body is at rest, its velocity is zero. If the body moves with a constant velocity, its acceleration is zero. When the velocity of a body changes, the acceleration is not necessarily zero.