Mechanical Engineering - Engineering Mechanics - Discussion

If it is vacuum then external force is required to stop.

If not at some point the body goes to the rest position.

I think option (a) is correct as -> Unless force external from the system is applied the system will continue to maintain its condition of constant motion or of stationary position.

Conservation of ENERGY.

It's true that motion is a change in displacement, but that doesn't need the continuous addition of energy to maintain as the conditions are always IDEAL in such questions.

Moreover, it's changed in motion which points toward change in energy not a change of position (Displacement). So motion in any direction is possible for a system that has a constant level of energy. (Imagine a ball in space which not in the influence of gravity from a body > if you give it a push it will start to travel with a constant velocity, NOW for this ball the total momentum of the system of masses (ball itself) in any direction remains constant unless acted upon by an external force in that direction. MEANING unless a force (or a force field) interferes with this system (WHICH (Force or force field) will be labelled EXTERNAL) the ball will go on its way beyond infinity (Literally).

It is the law of conservation of momentum.

According to the law of conservation of energy, the energy neither be created nor be destroyed.

Depending upon its energy and its system it can changes the direction.

This is by principle of conservation of linear momentum.

Principle of conservation of energy stated that energy can neither be created nor destroy.

According to the law of conservation of energy, the energy neither be created nor be destroyed.

In physics, the law of conservation of energy states that the total energy of an isolated system remains constant"it is said to be conserved over time. Energy can neither be created nor destroyed; rather, it transforms from one form to another.

Low of energy conservation is energy is a universal property and energy is not distrioid and not created only transform one form to another form.