# Acceleration in an inertial reference frame

• Swag ranger
In summary, the conversation discusses the concept of inertial reference frames and how an object's acceleration and velocity may differ in different inertial reference frames. The question is raised whether an object's acceleration and velocity are always zero in all inertial reference frames if it is zero in one. The responder suggests looking into the definition of inertial reference frames and clarifies that a reference frame is not necessarily associated with an object.

## Homework Statement

3. (a) If an object's acceleration is zero in one inertial reference frame then is its acceleration zero in all other inertial reference frames? (b) If an object's velocity is zero in one inertial reference frame then is its velocity zero in all other inertial reference frames?

## The Attempt at a Solution

I think it's going to be zero in both questions both I'm not so sure and I need an explanation

Hi Swag ranger,

Welcome to Physics Forums.

What do you know about inertial reference frames? How are they defined?

gneill said:
Hi Swag ranger,

Welcome to Physics Forums.

What do you know about inertial reference frames? How are they defined?
An object that does not accelerate

Swag ranger said:
An object that does not accelerate
No, not quite. A reference frame is not necessarily associated with a particular object. It's a coordinate system that has particular properties (particularly with respect to other inertial reference frames).

Suggestion: Take a look at the Wikipedia article regarding Inertial Reference Frames:

Inertial frame of reference - Wikipedia

## 1. What is an inertial reference frame?

An inertial reference frame is a coordinate system in which the laws of physics hold true and objects remain at a constant velocity unless acted upon by an external force.

## 2. How is acceleration defined in an inertial reference frame?

Acceleration in an inertial reference frame is defined as the rate of change of velocity over time. It can be calculated by dividing the change in velocity by the change in time.

## 3. What is the difference between acceleration in an inertial reference frame and a non-inertial reference frame?

In an inertial reference frame, acceleration is caused by an external force acting on an object. In a non-inertial reference frame, acceleration can also be caused by the frame itself accelerating.

## 4. Can acceleration in an inertial reference frame be negative?

Yes, acceleration in an inertial reference frame can be negative if the object is slowing down or accelerating in the opposite direction of its initial velocity.

## 5. What are some examples of acceleration in an inertial reference frame?

Examples of acceleration in an inertial reference frame include a car accelerating from a stop, a ball falling due to gravity, and a rocket launching into space.