Some small questions grouped together

[ritwik06]

Homework Statement

1. Is it possible for a particle to describe a curved path if no force acts on it? Is the answer reference frame dependent?
YES, when the body stays still but the frame describes a curved path. Then with respect to that frame the body will describe curves but no force would act on particle. Will we count pseudo force as a force?

2. It is sometimes heard that inertial frame of reference does not actually exists and is only an ideal concept. Comment.
I totally agree with the view. almost every thing practical has absolute acceleration. Ar my views compatible?

3. An object is placed far away from all objects that can exert force on it. A reference frame is taken by taking the origin and axes fix in this. Will th frame be necessarily inertial?
I think yes. But I am not very confident.

 

[ritwik06]

Homework Statement

1. Is it possible for a particle to describe a curved path if no force acts on it? Is the answer reference frame dependent?
YES, when the body stays still but the frame describes a curved path. Then with respect to that frame the body will describe curves but no force would act on particle. Will we count pseudo force as a force?

2. It is sometimes heard that inertial frame of reference does not actually exists and is only an ideal concept. Comment.
I totally agree with the view. almost every thing practical has absolute acceleration. Ar my views compatible?

3. An object is placed far away from all objects that can exert force on it. A reference frame is taken by taking the origin and axes fix in this. Will th frame be necessarily inertial?
I think yes. But I am not very confident.

Why aren't my questions answered?
As you can see, I have put on what I think is right. Do I need to do something more, in order that I get some help?

 

[thomate1]

I would like to address these questions one by one.

1. Is it possible for a particle to describe a curved path if no force acts on it? Is the answer reference frame dependent?

In classical mechanics, a particle can only describe a curved path if a force acts on it. This is known as Newton's First Law of Motion, which states that an object at rest will remain at rest and an object in motion will continue in motion in a straight line at a constant speed unless acted upon by an external force. However, in non-inertial reference frames (frames that are accelerating or rotating), objects may appear to follow curved paths due to the effects of fictitious forces such as the centrifugal force. Therefore, the answer to this question is reference frame dependent.

2. It is sometimes heard that inertial frame of reference does not actually exist and is only an ideal concept. Comment.

The concept of an inertial frame of reference is a fundamental principle in classical mechanics and is defined as a frame in which Newton's First Law of Motion holds true. In practice, it is difficult to find a perfectly inertial frame as all frames are subject to external forces and accelerations. However, for most practical purposes, we can consider a frame to be inertial if the effects of these external forces are negligible. So while it may be true that a perfectly inertial frame does not exist, the concept is still a useful and valid one in understanding the motion of objects.

3. An object is placed far away from all objects that can exert force on it. A reference frame is taken by taking the origin and axes fixed in this. Will the frame be necessarily inertial?

In this scenario, the frame would be considered inertial as there are no external forces acting on the object. However, it is important to note that the frame itself may not be perfectly inertial due to factors such as the rotation of the Earth or the motion of our galaxy. Again, the concept of an inertial frame is a useful one but may not exist in its purest form in practical situations.