**Imagine**, you are driving a car on a road.

Suppose that you increase the speed of your car.

At this moment,

When you increase the speed of your car, you are in a **non inertial frame of reference**.

In a similar way,

**Imagine**, you are sitting inside an aeroplane which is flying in the sky.

Suppose that a pilot increases the speed of an aeroplane.

Again, at this moment…

When a pilot increases the speed of an aeroplane, you are in a **non inertial frame of reference**.

In above cases,

As the frame of reference of a car and an aeroplane is accelerated,

Both (a car and an aeroplane) are considered to be in a non inertial frame of reference.

The question is,

**What is a non inertial frame of reference?**

Don’t worry, I’ll clear all your doubts.

In fact,

I’ll explain to you the exact meaning of a non inertial frame of reference with Real life examples.

Let’s get started with the definition.

## Non inertial frame of reference definition

In physics, the definition of non inertial frame of reference can be stated as:

*“A frame of reference which is** not moving with constant velocity** or is **accelerated** is known as **non inertial frame of reference**“*

In simple terms,

A frame of reference which is **accelerated** is known as the non inertial frame of reference.

After reading the above statement,

I think you might have not understood the exact meaning of non inertial frame of reference.

Let’s consider some real life examples to understand the above definition.

## Non inertial frame of reference examples

Here are some examples of non inertial frame of reference:

- A frame of reference of a
**rotating carousel**

- A frame of reference of a
**moving rickshaw**

- A frame of reference of a
**running boy**

- A frame of reference of a
**running athlete**

Any object whose reference frame (Or a frame of reference) is **accelerated **is said to be in a non inertial frame of reference.

To get a clear idea,

Let’s understand the above examples in detail. (One by One)

### #1 Rotating carousel

Imagine, you are sitting on a carousel.

Note that a carousel is **rotating** in a circular path.

Now let me ask you one question,

While sitting on a carousel, what is your frame of reference, is it Inertial or Non inertial?

I think the answer is simple.

You are in a non inertial frame of reference.

Why?

It’s because, while you are sitting on a carousel, your frame of reference is **accelerated**.

In short,

When a frame of reference is accelerated, it is known as the **non inertial frame of reference**.

### #2 Moving rickshaw

Imagine, you are sitting inside a rickshaw.

Note that a rickshaw is **moving** on a road.

Suppose that you increase the speed of a rickshaw.

Now, can you guess the frame of reference of a rickshaw, when its speed is increased?

It’s simple. Look,

When you increase the speed of a rickshaw, the frame of reference of a rickshaw is **accelerated**.

That’s why a rickshaw is in a non inertial frame of reference.

Or, remember this way:

When an object’s frame of reference is accelerated, an object is said to be in a **non inertial frame of reference**.

### #3 Running boy

Let’s consider a real life situation.

Suppose that you are **running** on the ground.

While running on the ground, what is your frame of reference, is it Inertial or Non inertial?

Have you guessed the answer?

It’s simple.

When running on the ground, your frame of reference is **accelerated**.

So, you are in a non inertial frame of reference.

That’s how you can remember the definition,

A frame of reference which is accelerated is known as the **non inertial frame of reference**.

### #4 Running athlete

Suppose that you have participated in a race.

Note that a race is about to begin.

After some time, a race begins and you have started **running**.

One simple question for you,

While running in a race, what do you think of your frame of reference?

YES, you have guessed the right answer !!

You are in a **non inertial reference frame**.

*(Because while running in a race, your frame of reference is **accelerated**)*

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What do you think, is it easy for you to understand this concept of non inertial frame of reference?

(Let me know in the **comments** below)