[kiranba002]

Is there an example of body being in the state of motion and rest simultaneously?

[jiten55]

Sit in an aeroplane!

From your standpoint you are at rest.

From standpoint of someone on the ground, you are in motion.

[JBeaucaire]

Put on roller skates and race up to speed, then just coast. You're not expending any more energy yourself (idling) but your kinetic energy has you still rolling on the skates (motion).

[vaskalr]

is there an example of body being in the state of motion and rest simultaneously?

Well it depends upon the frame of reference in which the observer is. If the observer is in inertial frame of reference then the body is in state of rest and motion simultaneously but if the observer is in non inertial frame of reference then the body can either be in rest or in motion.

[supriya _82]

well it depends upon the frame of reference in which the observer is. if the observer is in inertial frame of reference then the body is in state of rest and motion simultaneously but if the observer is in non inertial frame of reference then the body can either be in rest or in motion.

Well this is a question what Einstein's Special Theory of relativity addresses.
The inertial frame of reference, implies the frame of ref where ALL Newtonian Laws hold and this occurs in the Euclidian space. The Euclidian space and Laws of Newton are questioned in the Special theory of Relativity as all events cannot be accurately plotted. Hence the inertial frame of ref is discarded and the Euclidian space gives way to a curved Minkowski's space.
BUT IN EITHER CASE EACH BODY CAN BE AT REST OR IN MOTION RELATIVE TO OTHER.

[vaskalr]

Well this is a question what Einstein's Special Theory of relativity addresses.
The inertial frame of refrence, implies the frame of ref where ALL Newtonian Laws hold and this occurs in the Euclidian space. The Euclidian space and Laws of Newton are questioned in the Special theory of Relativity as all events cannot be accurately plotted. Hence the inertial frame of ref is discarded and the Euclidian space gives way to a curved Minkowski's space.
BUT IN EITHER CASE EACH BODY CAN BE AT REST OR IN MOTION RELATIVE TO OTHER.

What you said is partially right. Actually inertial frame of reference is not discarded, it is still used in world of science. Einstein said that the coordinates contract as a function of velocity of object and this velocity is relative to other object. This was actually not a new concept in the time of einstein also. Actually lorentz put the same concept but the logic given by einstein was more powerful. The root of einstein`s theory lies in Fizeau`s moving water experiment and Aragog`s moving prism experiment which are designed to find the true nature of light. These experiments gives rise to a new problem that light have a constant velocity but its speed depend upon speed of object. Scientists of that time consider light to be absolute frame mover(ie. Light moves in LUMINIFEROUS ETHER) but the null deflection michelson morley`s experiment fails ether concept and also the Bredley`s abretion experiment fails ether concept. Further in this race comes Dirac whose dirac sea challenges all theories. The emergence of antiparticals in passing of photons through vicinity of nucleus proves dirac theory. But it gives rise to numerous infinities. All these infinities were solved by Richard Fynmann. MY point here is if you carefully go through Fynnman`s model of universe which is the most celebrated model till date then there also you will find the two frame of references, i.e.. Inertial and non inertial frame of reference. SO, what I want to say is that it will be wrong if you says that inertial frame of reference is discarded.

[supriya _82]

I agree. But I did not want to get too technical on a simple question by Kiranba. Just wanted to correct what Jiten55 commented on your post as simply as I could.