Question

Name the property of matter that allows a body to remain at rest or in uniform motion unless it is acted upon by an external force:
(A) Inertia
(B) Elasticity
(C) Viscosity
(D) Density

Answer 1

This property is also known as Newton’s first law of motion which is the property of matter due to which a body continues to be in its position of rest or uniform motion unless and until an external force is applied on it. It is the amount of resistance to change in velocity or state of an object.

Complete answer:
The tendency of any item to resist change in its state of uniform motion or rest is known as inertia.
As a result, inertia may be called the tendency of an item to resist change in its velocity or motion of an object. In the absence of an unbalanced force, an object at rest has zero velocity and will continue to have zero velocity.
The resistance of any physical object that causes change in velocity of the object is known as inertia. Changes in the object's speed or direction of motion are included. The tendency of items to continue travelling in a straight line at a constant speed even when no forces are applied to them is an example of this feature.
The word inertia can refer to the object's amount of resistance to change in velocity or, in simpler terms, it is the resistance to a change in motion. It is determined by its mass and linear momentum, depending on the state of the body. As established by Newton in his first rule of motion, inertia is a shorthand for "the principle of inertia," which states that an item will continue to move at its same velocity until a force causes it to change the magnitude of velocity or direction of motion of the object.

Hence, the correct option is (A) Inertia.

Note:
Inertia is usually masked on Earth's surface by gravity, as well as the effects of friction and air resistance, which both slow things down (commonly to the point of rest). As a result, Aristotle, a Greek philosopher, came to the conclusion that objects could only move if they were given force.